Create base test class for custom views

.gitignore

@@ -33,3 +33,4 @@ build/
 *.iml
 
 art/
+*.actual.png

app/src/androidTest/java/org/isoron/uhabits/unit/views/RingViewTest.java

@@ -0,0 +1,48 @@
+/*
+ * 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.unit.views;
+
+import android.support.test.runner.AndroidJUnit4;
+import android.test.suitebuilder.annotation.SmallTest;
+
+import org.isoron.uhabits.helpers.ColorHelper;
+import org.isoron.uhabits.views.RingView;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.io.IOException;
+
+@RunWith(AndroidJUnit4.class)
+@SmallTest
+public class RingViewTest extends ViewTest
+{
+    @Test
+    public void renderTest1() throws IOException
+    {
+        RingView view = new RingView(targetContext);
+        view.setLabel("Hello world");
+        view.setPercentage(0.6f);
+        view.setColor(ColorHelper.palette[0]);
+        view.setMaxDiameter(dpToPixels(100));
+        measureView(dpToPixels(100), dpToPixels(100), view);
+
+        assertRenders(view, "Views/RingView/renderTest1.png");
+    }
+}

app/src/androidTest/java/org/isoron/uhabits/unit/views/ViewTest.java

@@ -0,0 +1,160 @@
+/*
+ * 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.unit.views;
+
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+import android.support.test.InstrumentationRegistry;
+import android.view.View;
+
+import org.isoron.uhabits.helpers.DialogHelper;
+import org.junit.Before;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+import static junit.framework.Assert.fail;
+
+public class ViewTest
+{
+    protected static final int SIMILARITY_CUTOFF = 6000;
+
+    protected Context testContext;
+    protected Context targetContext;
+
+    @Before
+    public void setup()
+    {
+        targetContext = InstrumentationRegistry.getTargetContext();
+        testContext = InstrumentationRegistry.getContext();
+    }
+
+    protected void measureView(int width, int height, View view)
+    {
+        int specWidth = View.MeasureSpec.makeMeasureSpec(width, View.MeasureSpec.EXACTLY);
+        int specHeight = View.MeasureSpec.makeMeasureSpec(height, View.MeasureSpec.EXACTLY);
+
+        view.measure(specWidth, specHeight);
+        view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight());
+    }
+
+    protected void assertRenders(View view, String expectedImagePath) throws IOException
+    {
+        StringBuilder errorMessage = new StringBuilder();
+
+        view.setDrawingCacheEnabled(true);
+        view.buildDrawingCache();
+
+        Bitmap actualBitmap = view.getDrawingCache();
+        Bitmap expectedBitmap = getBitmapFromAssets(expectedImagePath);
+        Bitmap scaledExpectedBitmap = Bitmap.createScaledBitmap(expectedBitmap,
+                actualBitmap.getWidth(), actualBitmap.getHeight(), false);
+
+        boolean similarEnough = true;
+        long distance;
+
+        if ((distance = compareHistograms(getHistogram(actualBitmap), getHistogram(
+                scaledExpectedBitmap))) > SIMILARITY_CUTOFF)
+        {
+            similarEnough = false;
+            errorMessage.append(String.format(
+                    "Rendered image has wrong histogram (distance=%d). ",
+                    distance));
+        }
+
+        if(!similarEnough)
+        {
+            String path = saveBitmap(expectedImagePath, actualBitmap);
+            errorMessage.append(String.format("Actual rendered image " + "saved to %s", path));
+            fail(errorMessage.toString());
+        }
+
+        actualBitmap.recycle();
+        expectedBitmap.recycle();
+        scaledExpectedBitmap.recycle();
+    }
+
+    private Bitmap getBitmapFromAssets(String path) throws IOException
+    {
+        InputStream stream = testContext.getAssets().open(path);
+        return BitmapFactory.decodeStream(stream);
+    }
+
+    private String saveBitmap(String filename, Bitmap bitmap)
+            throws IOException
+    {
+        String absolutePath = String.format("%s/Failed/%s", targetContext.getExternalCacheDir(),
+                filename.replaceAll("\\.png$", ".actual.png"));
+        new File(absolutePath).getParentFile().mkdirs();
+        FileOutputStream out = new FileOutputStream(absolutePath);
+        bitmap.compress(Bitmap.CompressFormat.PNG, 100, out);
+
+        return absolutePath;
+    }
+
+    private int[][] getHistogram(Bitmap bitmap)
+    {
+        int histogram[][] = new int[4][256];
+
+        for(int x = 0; x < bitmap.getWidth(); x++)
+        {
+            for(int y = 0; y < bitmap.getHeight(); y++)
+            {
+                int color = bitmap.getPixel(x, y);
+                int[] argb = new int[]{
+                        (color >> 24) & 0xff, //alpha
+                        (color >> 16) & 0xff, //red
+                        (color >>  8) & 0xff, //green
+                        (color      ) & 0xff  //blue
+                };
+
+                histogram[0][argb[0]]++;
+                histogram[1][argb[1]]++;
+                histogram[2][argb[2]]++;
+                histogram[3][argb[3]]++;
+            }
+        }
+
+        return histogram;
+    }
+
+    private long compareHistograms(int[][] actualHistogram, int[][] expectedHistogram)
+    {
+        long distance = 0;
+
+        for(int i = 0; i < 255; i ++)
+        {
+            distance += Math.abs(actualHistogram[0][i] - expectedHistogram[0][i]);
+            distance += Math.abs(actualHistogram[1][i] - expectedHistogram[1][i]);
+            distance += Math.abs(actualHistogram[2][i] - expectedHistogram[2][i]);
+            distance += Math.abs(actualHistogram[3][i] - expectedHistogram[3][i]);
+        }
+
+        return distance;
+    }
+
+    protected int dpToPixels(int dp)
+    {
+        return (int) DialogHelper.dpToPixels(targetContext, dp);
+    }
+}

app/src/main/java/org/isoron/uhabits/views/RingView.java

@@ -29,11 +29,11 @@ import android.text.Layout;
 import android.text.StaticLayout;
 import android.text.TextPaint;
 import android.util.AttributeSet;
+import android.util.Log;
 import android.view.View;
 
-import org.isoron.uhabits.helpers.ColorHelper;
-import org.isoron.uhabits.helpers.DialogHelper;
 import org.isoron.uhabits.R;
+import org.isoron.uhabits.helpers.DialogHelper;
 
 public class RingView extends View
 {
@@ -48,10 +48,16 @@ public class RingView extends View
     private int width;
     private int height;
     private float diameter;
+
     private float maxDiameter;
     private float textSize;
     private int fadedTextColor;
 
+    public RingView(Context context)
+    {
+        super(context);
+        init();
+    }
 
     public RingView(Context context, AttributeSet attrs)
     {
@@ -59,25 +65,28 @@ public class RingView extends View
 
         this.label = DialogHelper.getAttribute(context, attrs, "label");
         this.maxDiameter = DialogHelper.getFloatAttribute(context, attrs, "maxDiameter");
-
         this.maxDiameter = DialogHelper.dpToPixels(context, maxDiameter);
-        this.textSize = getResources().getDimension(R.dimen.smallTextSize);
-        this.color = ColorHelper.palette[7];
-        this.percentage = 0.75f;
         init();
     }
 
     public void setColor(int color)
     {
         this.color = color;
-        pRing.setColor(color);
-        postInvalidate();
+    }
+
+    public void setMaxDiameter(float maxDiameter)
+    {
+        this.maxDiameter = maxDiameter;
+    }
+
+    public void setLabel(String label)
+    {
+        this.label = label;
     }
 
     public void setPercentage(float percentage)
     {
         this.percentage = percentage;
-        postInvalidate();
     }
 
     private void init()
@@ -88,6 +97,8 @@ public class RingView extends View
         pRing.setTextAlign(Paint.Align.CENTER);
 
         fadedTextColor = getResources().getColor(R.color.fadedTextColor);
+        textSize = getResources().getDimension(R.dimen.smallTextSize);
+        Log.d("RingView", String.format("textSize=%f", textSize));
 
         rect = new RectF();
     }