Replace HistoryChart by new Kotlin implementation

android/uhabits-android/src/androidTest/java/org/isoron/platform/gui/AndroidCanvasTest.kt

@@ -30,7 +30,7 @@ class AndroidCanvasTest : BaseViewTest() {
         val bmp = Bitmap.createBitmap(1000, 800, Bitmap.Config.ARGB_8888)
         val canvas = AndroidCanvas()
         canvas.context = testContext
-        canvas.density = 2.0
+        canvas.innerDensity = 2.0
         canvas.innerCanvas = android.graphics.Canvas(bmp)
         canvas.innerBitmap = bmp
         canvas.drawTestImage()

android/uhabits-android/src/androidTest/java/org/isoron/uhabits/activities/common/views/HistoryChartTest.java

@@ -1,142 +0,0 @@
-/*
- * Copyright (C) 2016 Álinson Santos Xavier <isoron@gmail.com>
- *
- * This file is part of Loop Habit Tracker.
- *
- * Loop Habit Tracker is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by the
- * Free Software Foundation, either version 3 of the License, or (at your
- * option) any later version.
- *
- * Loop Habit Tracker is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
- * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-package org.isoron.uhabits.activities.common.views;
-
-import androidx.test.ext.junit.runners.*;
-import androidx.test.filters.*;
-
-import org.apache.commons.lang3.*;
-import org.isoron.uhabits.*;
-import org.isoron.uhabits.core.models.*;
-import org.isoron.uhabits.core.ui.callbacks.*;
-import org.isoron.uhabits.core.utils.*;
-import org.isoron.uhabits.utils.*;
-import org.junit.*;
-import org.junit.runner.*;
-
-import static org.mockito.Mockito.*;
-
-@RunWith(AndroidJUnit4.class)
-@MediumTest
-public class HistoryChartTest extends BaseViewTest
-{
-    private static final String BASE_PATH = "common/HistoryChart/";
-
-    private HistoryChart chart;
-
-    private Habit habit;
-
-    Timestamp today;
-
-    private OnToggleCheckmarkListener onToggleEntryListener;
-
-    @Override
-    @Before
-    public void setUp()
-    {
-        super.setUp();
-
-        fixtures.purgeHabits(habitList);
-        habit = fixtures.createLongHabit();
-        today = new Timestamp(DateUtils.getStartOfToday());
-
-        Integer[] entries = habit
-                .getComputedEntries()
-                .getByInterval(today.minus(300), today)
-                .stream()
-                .map(Entry::getValue)
-                .toArray(Integer[]::new);
-
-        chart = new HistoryChart(targetContext);
-        chart.setSkipEnabled(true);
-        chart.setEntries(ArrayUtils.toPrimitive(entries));
-        chart.setColor(PaletteUtilsKt.toFixedAndroidColor(habit.getColor()));
-        measureView(chart, dpToPixels(400), dpToPixels(200));
-
-        onToggleEntryListener = mock(OnToggleCheckmarkListener.class);
-        chart.setOnToggleCheckmarkListener(onToggleEntryListener);
-    }
-
-    @Test
-    public void tapDate_atInvalidLocations() throws Throwable
-    {
-        chart.setIsEditable(true);
-        chart.tap(dpToPixels(118), dpToPixels(13)); // header
-        chart.tap(dpToPixels(336), dpToPixels(60)); // tomorrow's square
-        chart.tap(dpToPixels(370), dpToPixels(60)); // right axis
-        verifyNoMoreInteractions(onToggleEntryListener);
-    }
-
-    @Test
-    public void tapDate_withEditableView() throws Throwable
-    {
-        chart.setIsEditable(true);
-        chart.tap(dpToPixels(340), dpToPixels(40));
-        verify(onToggleEntryListener).onToggleEntry(today, Entry.SKIP);
-        verifyNoMoreInteractions(onToggleEntryListener);
-    }
-
-    @Test
-    public void tapDate_withEmptyHabit()
-    {
-        chart.setIsEditable(true);
-        chart.setEntries(new int[]{});
-        chart.tap(dpToPixels(340), dpToPixels(40));
-        verify(onToggleEntryListener).onToggleEntry(today, Entry.YES_MANUAL);
-        verifyNoMoreInteractions(onToggleEntryListener);
-    }
-
-    @Test
-    public void tapDate_withReadOnlyView() throws Throwable
-    {
-        chart.setIsEditable(false);
-        chart.tap(dpToPixels(340), dpToPixels(40));
-        verifyNoMoreInteractions(onToggleEntryListener);
-    }
-
-    @Test
-    public void testRender() throws Throwable
-    {
-        assertRenders(chart, BASE_PATH + "render.png");
-    }
-
-    @Test
-    public void testRender_withDataOffset() throws Throwable
-    {
-        chart.onScroll(null, null, -dpToPixels(150), 0);
-        chart.invalidate();
-
-        assertRenders(chart, BASE_PATH + "renderDataOffset.png");
-    }
-
-    @Test
-    public void testRender_withDifferentSize() throws Throwable
-    {
-        measureView(chart, dpToPixels(200), dpToPixels(200));
-        assertRenders(chart, BASE_PATH + "renderDifferentSize.png");
-    }
-
-    @Test
-    public void testRender_withTransparentBackground() throws Throwable
-    {
-        chart.setIsBackgroundTransparent(true);
-        assertRenders(chart, BASE_PATH + "renderTransparent.png");
-    }
-}

android/uhabits-android/src/androidTest/java/org/isoron/uhabits/activities/habits/show/views/HistoryCardViewTest.kt

@@ -25,6 +25,7 @@ import androidx.test.filters.MediumTest
 import org.isoron.uhabits.BaseViewTest
 import org.isoron.uhabits.R
 import org.isoron.uhabits.core.ui.screens.habits.show.views.HistoryCardPresenter
+import org.isoron.uhabits.core.ui.views.LightTheme
 import org.junit.Before
 import org.junit.Test
 import org.junit.runner.RunWith
@@ -47,7 +48,8 @@ class HistoryCardViewTest : BaseViewTest() {
             HistoryCardPresenter().present(
                 habit = habit,
                 firstWeekday = 1,
-                isSkipEnabled = false
+                isSkipEnabled = false,
+                theme = LightTheme(),
             )
         )
         measureView(view, 800f, 600f)

android/uhabits-android/src/main/java/org/isoron/platform/gui/AndroidCanvas.kt

@@ -29,19 +29,24 @@ import org.isoron.uhabits.utils.InterfaceUtils.getFontAwesome
 
 class AndroidCanvas : Canvas {
 
-    lateinit var innerCanvas: android.graphics.Canvas
     lateinit var context: Context
+
+    lateinit var innerCanvas: android.graphics.Canvas
     var innerBitmap: Bitmap? = null
-    var density = 1.0
+    var innerDensity = 1.0
+    var innerWidth = 0
+    var innerHeight = 0
+
     var paint = Paint().apply {
         isAntiAlias = true
     }
     var textPaint = TextPaint().apply {
         isAntiAlias = true
+        textAlign = Paint.Align.CENTER
     }
     var textBounds = Rect()
 
-    private fun Double.toDp() = (this * density).toFloat()
+    private fun Double.toDp() = (this * innerDensity).toFloat()
 
     override fun setColor(color: Color) {
         paint.color = color.toInt()
@@ -73,6 +78,25 @@ class AndroidCanvas : Canvas {
         rect(x, y, width, height)
     }
 
+    override fun fillRoundRect(
+        x: Double,
+        y: Double,
+        width: Double,
+        height: Double,
+        cornerRadius: Double,
+    ) {
+        paint.style = Paint.Style.FILL
+        innerCanvas.drawRoundRect(
+            x.toDp(),
+            y.toDp(),
+            (x + width).toDp(),
+            (y + height).toDp(),
+            cornerRadius.toDp(),
+            cornerRadius.toDp(),
+            paint,
+        )
+    }
+
     override fun drawRect(x: Double, y: Double, width: Double, height: Double) {
         paint.style = Paint.Style.STROKE
         rect(x, y, width, height)
@@ -89,11 +113,11 @@ class AndroidCanvas : Canvas {
     }
 
     override fun getHeight(): Double {
-        return innerCanvas.height / density
+        return innerHeight / innerDensity
     }
 
     override fun getWidth(): Double {
-        return innerCanvas.width / density
+        return innerWidth / innerDensity
     }
 
     override fun setFont(font: Font) {

android/uhabits-android/src/main/java/org/isoron/platform/gui/AndroidDataView.kt

@@ -31,7 +31,7 @@ import android.widget.Scroller
  */
 class AndroidDataView(
     context: Context,
-    attrs: AttributeSet,
+    attrs: AttributeSet? = null,
 ) : AndroidView<DataView>(context, attrs),
     GestureDetector.OnGestureListener,
     ValueAnimator.AnimatorUpdateListener {
@@ -99,7 +99,7 @@ class AndroidDataView(
     }
 
     private fun updateDataOffset() {
-        var newDataOffset: Int = scroller.currX / (view.dataColumnWidth * canvas.density).toInt()
+        var newDataOffset: Int = scroller.currX / (view.dataColumnWidth * canvas.innerDensity).toInt()
         newDataOffset = Math.max(0, newDataOffset)
         if (newDataOffset != view.dataOffset) {
             view.dataOffset = newDataOffset

android/uhabits-android/src/main/java/org/isoron/platform/gui/AndroidTestView.kt

@@ -28,7 +28,7 @@ class AndroidTestView(context: Context, attrs: AttributeSet) : android.view.View
     override fun onDraw(canvas: android.graphics.Canvas) {
         this.canvas.context = context
         this.canvas.innerCanvas = canvas
-        this.canvas.density = resources.displayMetrics.density.toDouble()
+        this.canvas.innerDensity = resources.displayMetrics.density.toDouble()
         this.canvas.drawTestImage()
     }
 }

android/uhabits-android/src/main/java/org/isoron/platform/gui/AndroidView.kt

@@ -24,7 +24,7 @@ import android.util.AttributeSet
 
 open class AndroidView<T : View>(
     context: Context,
-    attrs: AttributeSet,
+    attrs: AttributeSet? = null,
 ) : android.view.View(context, attrs) {
 
     lateinit var view: T
@@ -33,7 +33,9 @@ open class AndroidView<T : View>(
     override fun onDraw(canvas: android.graphics.Canvas) {
         this.canvas.context = context
         this.canvas.innerCanvas = canvas
-        this.canvas.density = resources.displayMetrics.density.toDouble()
+        this.canvas.innerWidth = width
+        this.canvas.innerHeight = height
+        this.canvas.innerDensity = resources.displayMetrics.density.toDouble()
         view.draw(this.canvas)
     }
 }

android/uhabits-android/src/main/java/org/isoron/uhabits/activities/common/dialogs/HistoryEditorDialog.java

@@ -30,17 +30,17 @@ import androidx.appcompat.app.*;
 import android.util.*;
 
 import org.isoron.uhabits.*;
-import org.isoron.uhabits.activities.common.views.*;
 import org.isoron.uhabits.core.commands.*;
 import org.isoron.uhabits.core.models.*;
 import org.isoron.uhabits.core.preferences.*;
 import org.isoron.uhabits.core.tasks.*;
 import org.isoron.uhabits.core.ui.callbacks.*;
 import org.isoron.uhabits.core.ui.screens.habits.show.views.*;
+import org.isoron.uhabits.core.ui.views.*;
 import org.isoron.uhabits.utils.*;
 import org.jetbrains.annotations.*;
 
-import static org.isoron.uhabits.utils.InterfaceUtils.*;
+import java.util.*;
 
 public class HistoryEditorDialog extends AppCompatDialogFragment
         implements DialogInterface.OnClickListener, CommandRunner.Listener
@@ -92,31 +92,31 @@ public class HistoryEditorDialog extends AppCompatDialogFragment
         commandRunner = app.getComponent().getCommandRunner();
         prefs = app.getComponent().getPreferences();
 
-        historyChart = new HistoryChart(context);
+//        historyChart = new HistoryChart(context);
-        historyChart.setOnToggleCheckmarkListener(onToggleCheckmarkListener);
+//        historyChart.setOnToggleCheckmarkListener(onToggleCheckmarkListener);
-        historyChart.setFirstWeekday(prefs.getFirstWeekday());
+//        historyChart.setFirstWeekday(prefs.getFirstWeekday());
-        historyChart.setSkipEnabled(prefs.isSkipEnabled());
+//        historyChart.setSkipEnabled(prefs.isSkipEnabled());
-
-        if (savedInstanceState != null)
-        {
-            long id = savedInstanceState.getLong("habit", -1);
-            if (id > 0) this.habit = habitList.getById(id);
-            historyChart.onRestoreInstanceState(
-                savedInstanceState.getParcelable("historyChart"));
-        }
-
-        int padding =
-            (int) getDimension(getContext(), R.dimen.history_editor_padding);
-
-        historyChart.setPadding(padding, 0, padding, 0);
-        historyChart.setIsEditable(true);
 
+//        if (savedInstanceState != null)
+//        {
+//            long id = savedInstanceState.getLong("habit", -1);
+//            if (id > 0) this.habit = habitList.getById(id);
+//            historyChart.onRestoreInstanceState(
+//                savedInstanceState.getParcelable("historyChart"));
+//        }
+//
+//        int padding =
+//            (int) getDimension(getContext(), R.dimen.history_editor_padding);
+//
+//        historyChart.setPadding(padding, 0, padding, 0);
+//        historyChart.setIsEditable(true);
+//
         AlertDialog.Builder builder = new AlertDialog.Builder(context);
         builder
             .setTitle(R.string.history)
-            .setView(historyChart)
+//            .setView(historyChart)
             .setPositiveButton(android.R.string.ok, this);
-
+//
         return builder.create();
     }
 
@@ -146,8 +146,8 @@ public class HistoryEditorDialog extends AppCompatDialogFragment
     @Override
     public void onSaveInstanceState(Bundle outState)
     {
-        outState.putLong("habit", habit.getId());
+//        outState.putLong("habit", habit.getId());
-        outState.putParcelable("historyChart", historyChart.onSaveInstanceState());
+//        outState.putParcelable("historyChart", historyChart.onSaveInstanceState());
     }
 
     public void setOnToggleCheckmarkListener(@NonNull OnToggleCheckmarkListener onToggleCheckmarkListener)
@@ -174,7 +174,7 @@ public class HistoryEditorDialog extends AppCompatDialogFragment
 
     private class RefreshTask implements Task
     {
-        public int[] checkmarks;
+        public List<HistoryChart.Square> checkmarks;
 
         @Override
         public void doInBackground()
@@ -182,9 +182,10 @@ public class HistoryEditorDialog extends AppCompatDialogFragment
             HistoryCardViewModel model = new HistoryCardPresenter().present(
                     habit,
                     prefs.getFirstWeekday(),
-                    prefs.isSkipEnabled()
+                    prefs.isSkipEnabled(),
+                    new LightTheme()
             );
-            checkmarks = model.getEntries();
+            checkmarks = model.getSeries();
         }
 
         @Override
@@ -194,9 +195,9 @@ public class HistoryEditorDialog extends AppCompatDialogFragment
                 return;
 
             int color = PaletteUtilsKt.toThemedAndroidColor(habit.getColor(), getContext());
-            historyChart.setColor(color);
+//            historyChart.setColor(color);
-            historyChart.setEntries(checkmarks);
+//            historyChart.setEntries(checkmarks);
-            historyChart.setNumerical(habit.isNumerical());
+//            historyChart.setNumerical(habit.isNumerical());
         }
     }
 }

android/uhabits-android/src/main/java/org/isoron/uhabits/activities/common/views/HistoryChart.java

@@ -1,553 +0,0 @@
-/*
- * Copyright (C) 2016 Álinson Santos Xavier <isoron@gmail.com>
- *
- * This file is part of Loop Habit Tracker.
- *
- * Loop Habit Tracker is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by the
- * Free Software Foundation, either version 3 of the License, or (at your
- * option) any later version.
- *
- * Loop Habit Tracker is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
- * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-package org.isoron.uhabits.activities.common.views;
-
-import android.content.*;
-import android.graphics.*;
-import android.graphics.Color;
-import android.graphics.Paint.*;
-import android.util.*;
-import android.view.*;
-
-import androidx.annotation.*;
-import androidx.annotation.Nullable;
-
-import org.isoron.uhabits.*;
-import org.isoron.uhabits.core.models.*;
-import org.isoron.uhabits.core.ui.callbacks.*;
-import org.isoron.uhabits.core.utils.*;
-import org.isoron.uhabits.utils.*;
-import org.jetbrains.annotations.*;
-
-import java.text.*;
-import java.util.*;
-
-import static org.isoron.uhabits.utils.InterfaceUtils.*;
-import static org.isoron.uhabits.core.models.Entry.*;
-
-public class HistoryChart extends ScrollableChart
-{
-    private int[] checkmarks;
-
-    private Paint pSquareBg, pSquareFg, pTextHeader;
-
-    private float squareSpacing;
-
-    private float squareTextOffset;
-
-    private float headerTextOffset;
-
-    private float columnWidth;
-
-    private float columnHeight;
-
-    private int nColumns;
-
-    private SimpleDateFormat dfMonth;
-
-    private SimpleDateFormat dfYear;
-
-    private Calendar baseDate;
-
-    private int nDays;
-
-    /**
-     * 0-based-position of today in the column
-     */
-    private int todayPositionInColumn;
-
-    private int colors[];
-
-    private int textColors[];
-
-    private RectF baseLocation;
-
-    private int primaryColor;
-
-    private boolean isBackgroundTransparent;
-
-    private int reverseTextColor;
-
-    private int backgroundColor;
-
-    private boolean isEditable;
-
-    private String previousMonth;
-
-    private String previousYear;
-
-    private float headerOverflow = 0;
-
-    private boolean isNumerical = false;
-
-    private int firstWeekday = Calendar.SUNDAY;
-
-    @NonNull
-    private OnToggleCheckmarkListener onToggleCheckmarkListener;
-
-    private boolean skipsEnabled;
-
-    public HistoryChart(Context context)
-    {
-        super(context);
-        init();
-    }
-
-    public HistoryChart(Context context, AttributeSet attrs)
-    {
-        super(context, attrs);
-        init();
-    }
-
-    @Override
-    public void onLongPress(MotionEvent e)
-    {
-        onSingleTapUp(e);
-    }
-
-    @Override
-    public boolean onSingleTapUp(MotionEvent e)
-    {
-        float x, y;
-        try
-        {
-            int pointerId = e.getPointerId(0);
-            x = e.getX(pointerId);
-            y = e.getY(pointerId);
-        }
-        catch (RuntimeException ex)
-        {
-            // Android often throws IllegalArgumentException here. Apparently,
-            // the pointer id may become invalid shortly after calling
-            // e.getPointerId.
-            return false;
-        }
-        return tap(x, y);
-    }
-
-    public boolean tap(float x, float y)
-    {
-        if (!isEditable) return false;
-        performHapticFeedback(HapticFeedbackConstants.KEYBOARD_TAP);
-
-        final Timestamp timestamp = positionToTimestamp(x, y);
-        if (timestamp == null) return false;
-
-        Timestamp today = DateUtils.getTodayWithOffset();
-        int newValue = YES_MANUAL;
-        int offset = timestamp.daysUntil(today);
-        if (offset < checkmarks.length)
-        {
-            if(skipsEnabled)
-                newValue = Entry.Companion.nextToggleValueWithSkip(checkmarks[offset]);
-            else
-                newValue = Entry.Companion.nextToggleValueWithoutSkip(checkmarks[offset]);
-        }
-
-        onToggleCheckmarkListener.onToggleEntry(timestamp, newValue);
-        postInvalidate();
-        return true;
-
-    }
-
-    public void populateWithRandomData()
-    {
-        Random random = new Random();
-        checkmarks = new int[100];
-
-        for (int i = 0; i < 100; i++)
-            if (random.nextFloat() < 0.3) checkmarks[i] = 2;
-
-        for (int i = 0; i < 100 - 7; i++)
-        {
-            int count = 0;
-            for (int j = 0; j < 7; j++)
-                if (checkmarks[i + j] != 0) count++;
-
-            if (count >= 3) checkmarks[i] = Math.max(checkmarks[i], 1);
-        }
-    }
-
-    public void setEntries(int[] checkmarks)
-    {
-        this.checkmarks = checkmarks;
-        postInvalidate();
-    }
-
-    public void setColor(int color)
-    {
-        this.primaryColor = color;
-        initColors();
-        postInvalidate();
-    }
-
-    public void setOnToggleCheckmarkListener(@NonNull OnToggleCheckmarkListener onToggleCheckmarkListener)
-    {
-        this.onToggleCheckmarkListener = onToggleCheckmarkListener;
-    }
-
-    public void setNumerical(boolean numerical)
-    {
-        isNumerical = numerical;
-        postInvalidate();
-    }
-
-    public void setIsBackgroundTransparent(boolean isBackgroundTransparent)
-    {
-        this.isBackgroundTransparent = isBackgroundTransparent;
-        initColors();
-    }
-
-    public void setSkipEnabled(boolean value)
-    {
-        this.skipsEnabled = value;
-    }
-
-    public void setIsEditable(boolean isEditable)
-    {
-        this.isEditable = isEditable;
-    }
-
-    public void setFirstWeekday(int firstWeekday)
-    {
-        this.firstWeekday = firstWeekday;
-        postInvalidate();
-    }
-
-    protected void initPaints()
-    {
-        pTextHeader = new Paint();
-        pTextHeader.setTextAlign(Align.LEFT);
-        pTextHeader.setAntiAlias(true);
-
-        pSquareBg = new Paint();
-        pSquareBg.setAntiAlias(true);
-
-        pSquareFg = new Paint();
-        pSquareFg.setAntiAlias(true);
-        pSquareFg.setTextAlign(Align.CENTER);
-    }
-
-    @Override
-    protected void onDraw(Canvas canvas)
-    {
-        super.onDraw(canvas);
-
-        baseLocation.set(0, 0, columnWidth - squareSpacing,
-            columnWidth - squareSpacing);
-        baseLocation.offset(getPaddingLeft(), getPaddingTop());
-
-        headerOverflow = 0;
-        previousMonth = "";
-        previousYear = "";
-        pTextHeader.setColor(textColors[1]);
-
-        updateDate();
-        GregorianCalendar currentDate = (GregorianCalendar) baseDate.clone();
-
-        for (int column = 0; column < nColumns - 1; column++)
-        {
-            drawColumn(canvas, baseLocation, currentDate, column);
-            baseLocation.offset(columnWidth, -columnHeight);
-        }
-
-        drawAxis(canvas, baseLocation);
-    }
-
-    @Override
-    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
-    {
-        int width = MeasureSpec.getSize(widthMeasureSpec);
-        int height = MeasureSpec.getSize(heightMeasureSpec);
-        setMeasuredDimension(width, height);
-    }
-
-    @Override
-    protected void onSizeChanged(int width,
-                                 int height,
-                                 int oldWidth,
-                                 int oldHeight)
-    {
-        if (height < 8) height = 200;
-        float baseSize = height / 8.0f;
-        setScrollerBucketSize((int) baseSize);
-
-        squareSpacing = dpToPixels(getContext(), 1.0f);
-        float maxTextSize = getDimension(getContext(), R.dimen.regularTextSize);
-        float textSize = height * 0.06f;
-        textSize = Math.min(textSize, maxTextSize);
-
-        pSquareFg.setTextSize(textSize);
-        pTextHeader.setTextSize(textSize);
-        squareTextOffset = pSquareFg.getFontSpacing() * 0.4f;
-        headerTextOffset = pTextHeader.getFontSpacing() * 0.3f;
-
-        float rightLabelWidth = getWeekdayLabelWidth() + headerTextOffset;
-        float horizontalPadding = getPaddingRight() + getPaddingLeft();
-
-        columnWidth = baseSize;
-        columnHeight = 8 * baseSize;
-        nColumns =
-            (int) ((width - rightLabelWidth - horizontalPadding) / baseSize) +
-            1;
-
-        updateDate();
-    }
-
-    private void drawAxis(Canvas canvas, RectF location)
-    {
-        float verticalOffset = pTextHeader.getFontSpacing() * 0.4f;
-
-        for (String day : DateUtils.getShortWeekdayNames(firstWeekday))
-        {
-            location.offset(0, columnWidth);
-            canvas.drawText(day, location.left + headerTextOffset,
-                location.centerY() + verticalOffset, pTextHeader);
-        }
-    }
-
-    private void drawColumn(Canvas canvas,
-                            RectF location,
-                            GregorianCalendar date,
-                            int column)
-    {
-        drawColumnHeader(canvas, location, date);
-        location.offset(0, columnWidth);
-
-        for (int j = 0; j < 7; j++)
-        {
-            if (!(column == nColumns - 2 && getDataOffset() == 0 &&
-                  j > todayPositionInColumn))
-            {
-                int checkmarkOffset =
-                    getDataOffset() * 7 + nDays - 7 * (column + 1) +
-                    todayPositionInColumn - j;
-                drawSquare(canvas, location, date, checkmarkOffset);
-            }
-
-            date.add(Calendar.DAY_OF_MONTH, 1);
-            location.offset(0, columnWidth);
-        }
-    }
-
-    private void drawColumnHeader(Canvas canvas,
-                                  RectF location,
-                                  GregorianCalendar date)
-    {
-        String month = dfMonth.format(date.getTime());
-        String year = dfYear.format(date.getTime());
-
-        String text = null;
-        if (!month.equals(previousMonth)) text = previousMonth = month;
-        else if (!year.equals(previousYear)) text = previousYear = year;
-
-        if (text != null)
-        {
-            canvas.drawText(text, location.left + headerOverflow,
-                location.bottom - headerTextOffset, pTextHeader);
-            headerOverflow +=
-                pTextHeader.measureText(text) + columnWidth * 0.2f;
-        }
-
-        headerOverflow = Math.max(0, headerOverflow - columnWidth);
-    }
-
-    private void drawSquare(Canvas canvas,
-                            RectF location,
-                            GregorianCalendar date,
-                            int checkmarkOffset)
-    {
-
-        int checkmark = 0;
-        if (checkmarkOffset >= checkmarks.length)
-        {
-            pSquareBg.setColor(colors[0]);
-            pSquareFg.setColor(textColors[1]);
-        }
-        else
-        {
-            checkmark = checkmarks[checkmarkOffset];
-            if(checkmark <= 0)
-            {
-                pSquareBg.setColor(colors[0]);
-                pSquareFg.setColor(textColors[1]);
-            }
-            else if (isNumerical || checkmark == YES_MANUAL)
-            {
-                pSquareBg.setColor(colors[2]);
-                pSquareFg.setColor(textColors[2]);
-            }
-            else
-            {
-                pSquareBg.setColor(colors[1]);
-                pSquareFg.setColor(textColors[2]);
-            }
-        }
-
-        float round = dpToPixels(getContext(), 2);
-        canvas.drawRoundRect(location, round, round, pSquareBg);
-
-        if (!isNumerical && checkmark == SKIP)
-        {
-            pSquareBg.setColor(backgroundColor);
-            pSquareBg.setStrokeWidth(columnWidth * 0.025f);
-
-            canvas.save();
-            canvas.clipRect(location);
-            float offset = - columnWidth;
-            for (int k = 0; k < 10; k++)
-            {
-                offset += columnWidth / 5;
-                canvas.drawLine(location.left + offset,
-                                location.bottom,
-                                location.right + offset,
-                                location.top,
-                                pSquareBg);
-            }
-            canvas.restore();
-        }
-
-        String text = Integer.toString(date.get(Calendar.DAY_OF_MONTH));
-        canvas.drawText(text, location.centerX(),
-            location.centerY() + squareTextOffset, pSquareFg);
-    }
-
-    private float getWeekdayLabelWidth()
-    {
-        float width = 0;
-
-        for (String w : DateUtils.getShortWeekdayNames(firstWeekday))
-            width = Math.max(width, pSquareFg.measureText(w));
-
-        return width;
-    }
-
-    private void init()
-    {
-        isEditable = false;
-        checkmarks = new int[0];
-        onToggleCheckmarkListener = new OnToggleCheckmarkListener()
-        {
-            @Override
-            public void onToggleEntry(@NotNull Timestamp timestamp, int value)
-            {
-            }
-        };
-
-        initColors();
-        initPaints();
-        initDateFormats();
-        initRects();
-    }
-
-    private void initColors()
-    {
-        StyledResources res = new StyledResources(getContext());
-
-        if (isBackgroundTransparent)
-            primaryColor = ColorUtils.setMinValue(primaryColor, 0.75f);
-
-        int red = Color.red(primaryColor);
-        int green = Color.green(primaryColor);
-        int blue = Color.blue(primaryColor);
-
-        backgroundColor = res.getColor(R.attr.cardBgColor);
-
-        if (isBackgroundTransparent)
-        {
-            colors = new int[3];
-            colors[0] = Color.argb(16, 255, 255, 255);
-            colors[1] = Color.argb(128, red, green, blue);
-            colors[2] = primaryColor;
-
-            textColors = new int[3];
-            textColors[0] = Color.WHITE;
-            textColors[1] = Color.WHITE;
-            textColors[2] = Color.WHITE;
-            reverseTextColor = Color.WHITE;
-        }
-        else
-        {
-            colors = new int[3];
-            colors[0] = res.getColor(R.attr.lowContrastTextColor);
-            colors[1] = Color.argb(127, red, green, blue);
-            colors[2] = primaryColor;
-
-            textColors = new int[3];
-            textColors[0] = res.getColor(R.attr.lowContrastReverseTextColor);
-            textColors[1] = res.getColor(R.attr.mediumContrastTextColor);
-            textColors[2] = res.getColor(R.attr.highContrastReverseTextColor);
-            reverseTextColor = res.getColor(R.attr.highContrastReverseTextColor);
-        }
-    }
-
-    private void initDateFormats()
-    {
-        if (isInEditMode())
-        {
-            dfMonth = new SimpleDateFormat("MMM", Locale.getDefault());
-            dfYear = new SimpleDateFormat("yyyy", Locale.getDefault());
-        }
-        else
-        {
-            dfMonth = DateExtensionsKt.toSimpleDataFormat("MMM");
-            dfYear = DateExtensionsKt.toSimpleDataFormat("yyyy");
-        }
-    }
-
-    private void initRects()
-    {
-        baseLocation = new RectF();
-    }
-
-    @Nullable
-    private Timestamp positionToTimestamp(float x, float y)
-    {
-        int col = (int) (x / columnWidth);
-        int row = (int) (y / columnWidth);
-
-        if (row == 0) return null;
-        if (col == nColumns - 1) return null;
-
-        int offset = col * 7 + (row - 1);
-        Calendar date = (Calendar) baseDate.clone();
-        date.add(Calendar.DAY_OF_YEAR, offset);
-
-        if (DateUtils.getStartOfDayWithOffset(date.getTimeInMillis()) >
-            DateUtils.getStartOfTodayWithOffset()) return null;
-
-        return new Timestamp(date.getTimeInMillis());
-    }
-
-    private void updateDate()
-    {
-        baseDate = DateUtils.getStartOfTodayCalendarWithOffset();
-        baseDate.add(Calendar.DAY_OF_YEAR, -(getDataOffset() - 1) * 7);
-
-        nDays = (nColumns - 1) * 7;
-        int realWeekday =
-            DateUtils.getStartOfTodayCalendarWithOffset().get(Calendar.DAY_OF_WEEK);
-        todayPositionInColumn =
-            (7 + realWeekday - firstWeekday) % 7;
-
-        baseDate.add(Calendar.DAY_OF_YEAR, -nDays);
-        baseDate.add(Calendar.DAY_OF_YEAR, -todayPositionInColumn);
-    }
-}

android/uhabits-android/src/main/java/org/isoron/uhabits/activities/habits/show/views/HistoryCardView.kt

@@ -22,9 +22,12 @@ import android.content.Context
 import android.util.AttributeSet
 import android.view.LayoutInflater
 import android.widget.LinearLayout
+import org.isoron.platform.time.JavaLocalDateFormatter
 import org.isoron.uhabits.core.ui.screens.habits.show.views.HistoryCardViewModel
+import org.isoron.uhabits.core.ui.views.HistoryChart
 import org.isoron.uhabits.databinding.ShowHabitHistoryBinding
 import org.isoron.uhabits.utils.toThemedAndroidColor
+import java.util.Locale
 
 class HistoryCardView(context: Context, attrs: AttributeSet) : LinearLayout(context, attrs) {
 
@@ -37,14 +40,24 @@ class HistoryCardView(context: Context, attrs: AttributeSet) : LinearLayout(cont
     }
 
     fun update(data: HistoryCardViewModel) {
-        binding.historyChart.setFirstWeekday(data.firstWeekday)
+
-        binding.historyChart.setSkipEnabled(data.isSkipEnabled)
-        binding.historyChart.setEntries(data.entries)
         val androidColor = data.color.toThemedAndroidColor(context)
         binding.title.setTextColor(androidColor)
-        binding.historyChart.setColor(androidColor)
+        binding.chart.view = HistoryChart(
-        if (data.isNumerical) {
+            today = data.today,
-            binding.historyChart.setNumerical(true)
+            paletteColor = data.color,
-        }
+            theme = data.theme,
+            dateFormatter = JavaLocalDateFormatter(Locale.getDefault())
+        ).apply {
+            series = data.series
+        }
+
+        // binding.historyChart.setFirstWeekday(data.firstWeekday)
+        // binding.historyChart.setSkipEnabled(data.isSkipEnabled)
+        // binding.historyChart.setEntries(data.entries)
+        // binding.historyChart.setColor(androidColor)
+        // if (data.isNumerical) {
+        //     binding.historyChart.setNumerical(true)
+        // }
     }
 }

android/uhabits-android/src/main/java/org/isoron/uhabits/widgets/HistoryWidget.kt

@@ -22,11 +22,15 @@ package org.isoron.uhabits.widgets
 import android.app.PendingIntent
 import android.content.Context
 import android.view.View
-import org.isoron.uhabits.activities.common.views.HistoryChart
+import org.isoron.platform.gui.AndroidDataView
+import org.isoron.platform.time.JavaLocalDateFormatter
 import org.isoron.uhabits.core.models.Habit
 import org.isoron.uhabits.core.ui.screens.habits.show.views.HistoryCardPresenter
-import org.isoron.uhabits.utils.toThemedAndroidColor
+import org.isoron.uhabits.core.ui.views.DarkTheme
+import org.isoron.uhabits.core.ui.views.HistoryChart
+import org.isoron.uhabits.core.utils.DateUtils
 import org.isoron.uhabits.widgets.views.GraphWidgetView
+import java.util.Locale
 
 class HistoryWidget(
     context: Context,
@@ -47,18 +51,25 @@ class HistoryWidget(
             habit = habit,
             isSkipEnabled = prefs.isSkipEnabled,
             firstWeekday = prefs.firstWeekday,
+            theme = DarkTheme(),
         )
-        (widgetView.dataView as HistoryChart).apply {
+        (widgetView.dataView as AndroidDataView).apply {
-            setFirstWeekday(model.firstWeekday)
+            (this.view as HistoryChart).series = model.series
-            setSkipEnabled(model.isSkipEnabled)
-            setColor(model.color.toThemedAndroidColor(context))
-            setEntries(model.entries)
-            setNumerical(model.isNumerical)
         }
     }
 
     override fun buildView() =
-        GraphWidgetView(context, HistoryChart(context)).apply {
+        GraphWidgetView(
+            context,
+            AndroidDataView(context).apply {
+                view = HistoryChart(
+                    today = DateUtils.getTodayWithOffset().toLocalDate(),
+                    paletteColor = habit.color,
+                    theme = DarkTheme(),
+                    dateFormatter = JavaLocalDateFormatter(Locale.getDefault())
+                )
+            }
+        ).apply {
             setTitle(habit.name)
         }
 

android/uhabits-android/src/main/res/layout/show_habit_history.xml

@@ -29,8 +29,8 @@
         style="@style/CardHeader"
         android:text="@string/calendar"/>
 
-    <org.isoron.uhabits.activities.common.views.HistoryChart
+    <org.isoron.platform.gui.AndroidDataView
-        android:id="@+id/historyChart"
+        android:id="@+id/chart"
         android:layout_width="match_parent"
         android:layout_height="160dp"/>
 

android/uhabits-core/src/main/java/org/isoron/platform/gui/Canvas.kt

@@ -34,6 +34,7 @@ interface Canvas {
     fun drawLine(x1: Double, y1: Double, x2: Double, y2: Double)
     fun drawText(text: String, x: Double, y: Double)
     fun fillRect(x: Double, y: Double, width: Double, height: Double)
+    fun fillRoundRect(x: Double, y: Double, width: Double, height: Double, cornerRadius: Double)
     fun drawRect(x: Double, y: Double, width: Double, height: Double)
     fun getHeight(): Double
     fun getWidth(): Double

android/uhabits-core/src/main/java/org/isoron/platform/gui/Color.kt

@@ -19,8 +19,6 @@
 
 package org.isoron.platform.gui
 
-data class PaletteColor(val index: Int)
-
 data class Color(
     val red: Double,
     val green: Double,
@@ -48,4 +46,11 @@ data class Color(
             alpha * (1 - weight) + other.alpha * weight
         )
     }
+
+    fun contrast(other: Color): Double {
+        val l1 = this.luminosity
+        val l2 = other.luminosity
+        val relativeLuminosity = (l1 + 0.05) / (l2 + 0.05)
+        return if (relativeLuminosity >= 1) relativeLuminosity else 1 / relativeLuminosity
+    }
 }

android/uhabits-core/src/main/java/org/isoron/platform/gui/JavaCanvas.kt

@@ -30,6 +30,7 @@ import java.awt.RenderingHints.VALUE_ANTIALIAS_ON
 import java.awt.RenderingHints.VALUE_FRACTIONALMETRICS_ON
 import java.awt.RenderingHints.VALUE_TEXT_ANTIALIAS_ON
 import java.awt.font.FontRenderContext
+import java.awt.geom.RoundRectangle2D
 import java.awt.image.BufferedImage
 import kotlin.math.roundToInt
 
@@ -115,6 +116,25 @@ class JavaCanvas(
         g2d.fillRect(toPixel(x), toPixel(y), toPixel(width), toPixel(height))
     }
 
+    override fun fillRoundRect(
+        x: Double,
+        y: Double,
+        width: Double,
+        height: Double,
+        cornerRadius: Double
+    ) {
+        g2d.fill(
+            RoundRectangle2D.Double(
+                toPixel(x).toDouble(),
+                toPixel(y).toDouble(),
+                toPixel(width).toDouble(),
+                toPixel(height).toDouble(),
+                toPixel(cornerRadius).toDouble(),
+                toPixel(cornerRadius).toDouble(),
+            )
+        )
+    }
+
     override fun drawRect(x: Double, y: Double, width: Double, height: Double) {
         g2d.drawRect(toPixel(x), toPixel(y), toPixel(width), toPixel(height))
     }

android/uhabits-core/src/main/java/org/isoron/uhabits/core/ui/screens/habits/show/ShowHabit.kt

@@ -96,6 +96,7 @@ class ShowHabitPresenter {
                 habit = habit,
                 firstWeekday = preferences.firstWeekday,
                 isSkipEnabled = preferences.isSkipEnabled,
+                theme = theme,
             ),
             bar = BarCardPresenter().present(
                 habit = habit,

android/uhabits-core/src/main/java/org/isoron/uhabits/core/ui/screens/habits/show/views/HistoryCard.kt

@@ -19,16 +19,24 @@
 
 package org.isoron.uhabits.core.ui.screens.habits.show.views
 
+import org.isoron.platform.time.LocalDate
+import org.isoron.uhabits.core.models.Entry
+import org.isoron.uhabits.core.models.Entry.Companion.SKIP
+import org.isoron.uhabits.core.models.Entry.Companion.YES_AUTO
+import org.isoron.uhabits.core.models.Entry.Companion.YES_MANUAL
 import org.isoron.uhabits.core.models.Habit
 import org.isoron.uhabits.core.models.PaletteColor
+import org.isoron.uhabits.core.ui.views.HistoryChart
+import org.isoron.uhabits.core.ui.views.Theme
 import org.isoron.uhabits.core.utils.DateUtils
+import kotlin.math.max
 
 data class HistoryCardViewModel(
     val color: PaletteColor,
-    val entries: IntArray,
     val firstWeekday: Int,
-    val isNumerical: Boolean,
+    val series: List<HistoryChart.Square>,
-    val isSkipEnabled: Boolean,
+    val theme: Theme,
+    val today: LocalDate,
 )
 
 class HistoryCardPresenter {
@@ -36,18 +44,37 @@ class HistoryCardPresenter {
         habit: Habit,
         firstWeekday: Int,
         isSkipEnabled: Boolean,
+        theme: Theme,
     ): HistoryCardViewModel {
         val today = DateUtils.getTodayWithOffset()
         val oldest = habit.computedEntries.getKnown().lastOrNull()?.timestamp ?: today
-        val entries =
+        val entries = habit.computedEntries.getByInterval(oldest, today)
-            habit.computedEntries.getByInterval(oldest, today).map { it.value }.toIntArray()
+        val series = if (habit.isNumerical) {
+            entries.map {
+                Entry(it.timestamp, max(0, it.value))
+            }.map {
+                when (it.value) {
+                    0 -> HistoryChart.Square.OFF
+                    else -> HistoryChart.Square.ON
+                }
+            }
+        } else {
+            entries.map {
+                when (it.value) {
+                    YES_MANUAL -> HistoryChart.Square.ON
+                    YES_AUTO -> HistoryChart.Square.DIMMED
+                    SKIP -> HistoryChart.Square.HATCHED
+                    else -> HistoryChart.Square.OFF
+                }
+            }
+        }
 
         return HistoryCardViewModel(
-            entries = entries,
             color = habit.color,
             firstWeekday = firstWeekday,
-            isNumerical = habit.isNumerical,
+            today = today.toLocalDate(),
-            isSkipEnabled = isSkipEnabled,
+            theme = theme,
+            series = series,
         )
     }
 }

android/uhabits-core/src/main/java/org/isoron/uhabits/core/ui/views/HistoryChart.kt

@@ -21,53 +21,74 @@ package org.isoron.uhabits.core.ui.views
 
 import org.isoron.platform.gui.Canvas
 import org.isoron.platform.gui.Color
+import org.isoron.platform.gui.DataView
 import org.isoron.platform.gui.TextAlign
-import org.isoron.platform.gui.View
 import org.isoron.platform.time.LocalDate
 import org.isoron.platform.time.LocalDateFormatter
+import org.isoron.uhabits.core.models.PaletteColor
 import kotlin.math.floor
 import kotlin.math.round
 
-class CalendarChart(
+class HistoryChart(
     var today: LocalDate,
-    var color: Color,
+    var paletteColor: PaletteColor,
     var theme: Theme,
     var dateFormatter: LocalDateFormatter
-) : View {
+) : DataView {
 
-    var padding = 5.0
+    enum class Square {
-    var backgroundColor = Color(0xFFFFFF)
+        ON,
+        OFF,
+        DIMMED,
+        HATCHED,
+    }
+
+    // Data
+    var series = listOf<Square>()
+
+    // Style
+    var padding = 0.0
     var squareSpacing = 1.0
-    var series = listOf<Double>()
+    override var dataOffset = 0
-    var scrollPosition = 0
     private var squareSize = 0.0
 
+    var lastPrintedMonth = ""
+    var lastPrintedYear = ""
+
+    override val dataColumnWidth: Double
+        get() = squareSpacing + squareSize
+
     override fun draw(canvas: Canvas) {
         val width = canvas.getWidth()
         val height = canvas.getHeight()
-        canvas.setColor(backgroundColor)
+        canvas.setColor(theme.cardBackgroundColor)
         canvas.fillRect(0.0, 0.0, width, height)
         squareSize = round((height - 2 * padding) / 8.0)
         canvas.setFontSize(height * 0.06)
 
         val nColumns = floor((width - 2 * padding) / squareSize).toInt() - 2
         val todayWeekday = today.dayOfWeek
-        val topLeftOffset = (nColumns - 1 + scrollPosition) * 7 + todayWeekday.index
+        val topLeftOffset = (nColumns - 1 + dataOffset) * 7 + todayWeekday.index
         val topLeftDate = today.minus(topLeftOffset)
 
+        lastPrintedYear = ""
+        lastPrintedMonth = ""
+
+        // Draw main columns
         repeat(nColumns) { column ->
             val topOffset = topLeftOffset - 7 * column
             val topDate = topLeftDate.plus(7 * column)
             drawColumn(canvas, column, topDate, topOffset)
         }
 
+        // Draw week day names
         canvas.setColor(theme.mediumContrastTextColor)
         repeat(7) { row ->
             val date = topLeftDate.plus(row)
             canvas.setTextAlign(TextAlign.LEFT)
             canvas.drawText(
                 dateFormatter.shortWeekdayName(date),
-                padding + nColumns * squareSize + padding,
+                padding + nColumns * squareSize + squareSpacing * 3,
                 padding + squareSize * (row + 1) + squareSize / 2
             )
         }
@@ -97,22 +118,29 @@ class CalendarChart(
     }
 
     private fun drawHeader(canvas: Canvas, column: Int, date: LocalDate) {
-        if (date.day >= 8) return
-
         canvas.setColor(theme.mediumContrastTextColor)
-        if (date.month == 1) {
+        val monthText = dateFormatter.shortMonthName(date)
-            canvas.drawText(
+        val yearText = date.year.toString()
-                date.year.toString(),
+        val headerText: String
-                padding + column * squareSize + squareSize / 2,
+        when {
-                padding + squareSize / 2
+            monthText != lastPrintedMonth -> {
-            )
+                headerText = monthText
-        } else {
+                lastPrintedMonth = monthText
-            canvas.drawText(
-                dateFormatter.shortMonthName(date),
-                padding + column * squareSize + squareSize / 2,
-                padding + squareSize / 2
-            )
             }
+            yearText != lastPrintedYear -> {
+                headerText = yearText
+                lastPrintedYear = headerText
+            }
+            else -> {
+                headerText = ""
+            }
+        }
+        canvas.setTextAlign(TextAlign.LEFT)
+        canvas.drawText(
+            headerText,
+            padding + column * squareSize,
+            padding + squareSize / 2
+        )
     }
 
     private fun drawSquare(
@@ -125,19 +153,46 @@ class CalendarChart(
         offset: Int
     ) {
 
-        var value = if (offset >= series.size) 0.0 else series[offset]
+        val value = if (offset >= series.size) Square.OFF else series[offset]
-        value = round(value * 5.0) / 5.0
+        val squareColor: Color
-
+        val color = theme.color(paletteColor.paletteIndex)
-        var squareColor = color.blendWith(backgroundColor, 1 - value)
+        when (value) {
-        var textColor = backgroundColor
+            Square.ON -> {
-
+                squareColor = color
-        if (value == 0.0) squareColor = theme.lowContrastTextColor
+            }
-        if (squareColor.luminosity > 0.8)
+            Square.OFF -> {
-            textColor = squareColor.blendWith(theme.highContrastTextColor, 0.5)
+                squareColor = theme.lowContrastTextColor
+            }
+            Square.DIMMED, Square.HATCHED -> {
+                squareColor = color.blendWith(theme.cardBackgroundColor, 0.5)
+            }
+        }
 
         canvas.setColor(squareColor)
-        canvas.fillRect(x, y, width, height)
+        canvas.fillRoundRect(x, y, width, height, width * 0.15)
+
+        if (value == Square.HATCHED) {
+            canvas.setStrokeWidth(0.75)
+            canvas.setColor(theme.cardBackgroundColor)
+            var k = width / 10
+            repeat(5) {
+                canvas.drawLine(x + k, y, x, y + k)
+                canvas.drawLine(
+                    x + width - k,
+                    y + height,
+                    x + width,
+                    y + height - k
+                )
+                k += width / 5
+            }
+        }
+
+        val c1 = squareColor.contrast(theme.cardBackgroundColor)
+        val c2 = squareColor.contrast(theme.mediumContrastTextColor)
+        val textColor = if (c1 > c2) theme.cardBackgroundColor else theme.mediumContrastTextColor
+
         canvas.setColor(textColor)
+        canvas.setTextAlign(TextAlign.CENTER)
         canvas.drawText(date.day.toString(), x + width / 2, y + width / 2)
     }
 }

android/uhabits-core/src/test/java/org/isoron/uhabits/core/ui/views/HistoryChartTest.kt

@@ -0,0 +1,100 @@
+/*
+ * Copyright (C) 2016-2019 Álinson Santos Xavier <isoron@gmail.com>
+ *
+ * This file is part of Loop Habit Tracker.
+ *
+ * Loop Habit Tracker is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or (at your
+ * option) any later version.
+ *
+ * Loop Habit Tracker is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.isoron.uhabits.components
+
+import kotlinx.coroutines.runBlocking
+import org.isoron.platform.gui.assertRenders
+import org.isoron.platform.time.JavaLocalDateFormatter
+import org.isoron.platform.time.LocalDate
+import org.isoron.uhabits.core.models.PaletteColor
+import org.isoron.uhabits.core.ui.views.DarkTheme
+import org.isoron.uhabits.core.ui.views.HistoryChart
+import org.isoron.uhabits.core.ui.views.HistoryChart.Square.DIMMED
+import org.isoron.uhabits.core.ui.views.HistoryChart.Square.HATCHED
+import org.isoron.uhabits.core.ui.views.HistoryChart.Square.OFF
+import org.isoron.uhabits.core.ui.views.HistoryChart.Square.ON
+import org.isoron.uhabits.core.ui.views.LightTheme
+import org.junit.Test
+import java.util.Locale
+
+class HistoryChartTest {
+    val base = "views/HistoryChart"
+    val fmt = JavaLocalDateFormatter(Locale.US)
+    val theme = LightTheme()
+    val view = HistoryChart(
+        LocalDate(2015, 1, 25),
+        PaletteColor(7),
+        theme,
+        fmt,
+    ).apply {
+        series = listOf(
+            2, // today
+            2, 1, 2, 1, 2, 1, 2,
+            2, 3, 3, 3, 3, 1, 2,
+            2, 1, 2, 1, 2, 2, 1,
+            1, 1, 1, 1, 2, 2, 2,
+            1, 3, 3, 3, 0, 0, 0,
+            0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 1, 1, 1, 1,
+            2, 2, 2, 3, 3, 3, 1,
+            1, 2, 1, 2, 1, 1, 2,
+            1, 2, 1, 1, 1, 1, 2,
+            2, 2, 2, 2, 2, 1, 1,
+            1, 1, 2, 2, 1, 2, 1,
+            1, 1, 1, 1, 2, 2, 2,
+        ).map {
+            when (it) {
+                3 -> HATCHED
+                2 -> ON
+                1 -> DIMMED
+                else -> OFF
+            }
+        }
+    }
+
+    // TODO: Label overflow
+    // TODO: Transparent
+    // TODO: onClick
+    // TODO: HistoryEditorDialog
+    // TODO: Remove excessive padding on widgets
+    // TODO: First day of the week
+
+    @Test
+    fun testDraw() = runBlocking {
+        assertRenders(400, 200, "$base/base.png", view)
+    }
+
+    @Test
+    fun testDrawDifferentSize() = runBlocking {
+        assertRenders(200, 200, "$base/small.png", view)
+    }
+
+    @Test
+    fun testDrawDarkTheme() = runBlocking {
+        view.theme = DarkTheme()
+        assertRenders(400, 200, "$base/dark.png", view)
+    }
+
+    @Test
+    fun testDrawOffset() = runBlocking {
+        view.dataOffset = 2
+        assertRenders(400, 200, "$base/scroll.png", view)
+    }
+}