Remove react-native; rewrite main screen in (native) swift

core/src/commonMain/kotlin/org/isoron/uhabits/Backend.kt

@@ -19,16 +19,19 @@
 
 package org.isoron.uhabits
 
+import org.isoron.uhabits.gui.*
 import org.isoron.uhabits.models.*
 import org.isoron.uhabits.utils.*
 
-class Backend(var databaseOpener: DatabaseOpener,
-              var fileOpener: FileOpener,
-              var log: Log) {
 
-    var database: Database
-    var habitsRepository: HabitRepository
-    var habits = mutableMapOf<Int, Habit>()
+class Backend(databaseOpener: DatabaseOpener,
+              fileOpener: FileOpener,
+              log: Log) {
+
+    private var database: Database
+    private var habitsRepository: HabitRepository
+    private var habits = mutableMapOf<Int, Habit>()
+    var theme: Theme = LightTheme()
 
     init {
         val dbFile = fileOpener.openUserFile("uhabits.db")
@@ -39,11 +42,14 @@ class Backend(var databaseOpener: DatabaseOpener,
     }
 
     fun getHabitList(): List<Map<String, *>> {
-        return habits.values.sortedBy { h -> h.position }.map { h ->
-            mapOf("key" to h.id.toString(),
-                  "name" to h.name,
-                  "color" to h.color.paletteIndex)
-        }
+        return habits.values
+                .filter { h -> !h.isArchived }
+                .sortedBy { h -> h.position }
+                .map { h ->
+                    mapOf("key" to h.id.toString(),
+                          "name" to h.name,
+                          "color" to h.color.index)
+                }
     }
 
     fun createHabit(name: String) {
@@ -52,7 +58,7 @@ class Backend(var databaseOpener: DatabaseOpener,
                           name = name,
                           description = "",
                           frequency = Frequency(1, 1),
-                          color = Color(3),
+                          color = PaletteColor(3),
                           isArchived = false,
                           position = habits.size,
                           unit = "",

core/src/commonMain/kotlin/org/isoron/uhabits/gui/Canvas.kt

@@ -0,0 +1,45 @@
+/*
+ * 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.gui
+
+enum class Font {
+    REGULAR,
+    BOLD,
+    FONT_AWESOME
+}
+
+interface Canvas {
+    fun setColor(color: Color)
+    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 drawRect(x: Double, y: Double, width: Double, height: Double)
+    fun getHeight(): Double
+    fun getWidth(): Double
+    fun setFont(font: Font)
+    fun setTextSize(size: Double)
+    fun setStrokeWidth(size: Double)
+    fun fillArc(centerX: Double,
+                centerY: Double,
+                radius: Double,
+                startAngle: Double,
+                swipeAngle: Double)
+    fun fillCircle(centerX: Double, centerY: Double, radius: Double)
+}

core/src/commonMain/kotlin/org/isoron/uhabits/gui/Colors.kt

@@ -17,23 +17,13 @@
  * with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
-package org.isoron.uhabits
+package org.isoron.uhabits.gui
 
-import org.isoron.uhabits.models.HabitRepository
-import org.isoron.uhabits.utils.*
-import org.junit.Before
+data class PaletteColor(val index: Int)
 
-open class BaseTest {
-    val fileOpener = JavaFileOpener()
-    val log = StandardLog()
-    val databaseOpener = JavaDatabaseOpener(log)
-    lateinit var db: Database
-
-    @Before
-    open fun setUp() {
-        val dbFile = fileOpener.openUserFile("test.sqlite3")
-        if (dbFile.exists()) dbFile.delete()
-        db = databaseOpener.open(dbFile)
-        db.migrateTo(LOOP_DATABASE_VERSION, fileOpener, log)
-    }
-}
+class Color(val argb: Int) {
+    val alpha = 1.0
+    val red   = ((argb shr 16) and 0xFF) / 255.0
+    val green = ((argb shr 8 ) and 0xFF) / 255.0
+    val blue  = ((argb shr 0 ) and 0xFF) / 255.0
+}

core/src/commonMain/kotlin/org/isoron/uhabits/gui/FontAwesome.kt

@@ -17,6 +17,11 @@
  * with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
-package org.isoron.uhabits.models
+package org.isoron.uhabits.gui
 
-class Timestamp(val unixTime: Long)
+class FontAwesome {
+    companion object {
+        val CHECK = "\uf00c"
+        val TIMES = "\uf00d"
+    }
+}

core/src/commonMain/kotlin/org/isoron/uhabits/gui/Themes.kt

@@ -0,0 +1,68 @@
+/*
+ * 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.gui
+
+abstract class Theme {
+    val toolbarColor = Color(0xffffff)
+
+    val lowContrastTextColor = Color(0xe0e0e0)
+    val mediumContrastTextColor = Color(0x808080)
+    val highContrastTextColor = Color(0x202020)
+
+    val cardBackgroundColor = Color(0xFFFFFF)
+    val appBackgroundColor = Color(0xf4f4f4)
+    val toolbarBackgroundColor = Color(0xf4f4f4)
+    val statusBarBackgroundColor = Color(0x333333)
+
+    val headerBackgroundColor = Color(0xeeeeee)
+    val headerBorderColor = Color(0xcccccc)
+    val headerTextColor = mediumContrastTextColor
+
+    val itemBackgroundColor = Color(0xffffff)
+
+    fun color(paletteIndex: Int): Color {
+        return when (paletteIndex) {
+            0 -> Color(0xD32F2F)
+            1 -> Color(0x512DA8)
+            2 -> Color(0xF57C00)
+            3 -> Color(0xFF8F00)
+            4 -> Color(0xF9A825)
+            5 -> Color(0xAFB42B)
+            6 -> Color(0x7CB342)
+            7 -> Color(0x388E3C)
+            8 -> Color(0x00897B)
+            9 -> Color(0x00ACC1)
+            10 -> Color(0x039BE5)
+            11 -> Color(0x1976D2)
+            12 -> Color(0x303F9F)
+            13 -> Color(0x5E35B1)
+            14 -> Color(0x8E24AA)
+            15 -> Color(0xD81B60)
+            16 -> Color(0x5D4037)
+            else -> Color(0x000000)
+        }
+    }
+
+    val checkmarkButtonSize = 48.0
+    val smallTextSize = 12.0
+    val regularTextSize = 17.0
+}
+
+class LightTheme : Theme()

core/src/commonMain/kotlin/org/isoron/uhabits/gui/components/CheckmarkButton.kt

@@ -0,0 +1,41 @@
+/*
+ * 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.gui.components.HabitList
+
+import org.isoron.uhabits.gui.*
+import org.isoron.uhabits.gui.components.*
+
+class CheckmarkButton(private val value: Int,
+                      private val color: Color,
+                      private val theme: Theme) : Component {
+    override fun draw(canvas: Canvas) {
+        canvas.setFont(Font.FONT_AWESOME)
+        canvas.setTextSize(theme.smallTextSize * 1.5)
+        canvas.setColor(when (value) {
+                            2 -> color
+                            else -> theme.lowContrastTextColor
+                        })
+        val text = when (value) {
+            0 -> FontAwesome.TIMES
+            else -> FontAwesome.CHECK
+        }
+        canvas.drawText(text, canvas.getWidth() / 2.0, canvas.getHeight() / 2.0)
+    }
+}

core/src/commonMain/kotlin/org/isoron/uhabits/gui/components/Component.kt

@@ -17,6 +17,10 @@
  * with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
-package org.isoron.uhabits.models
+package org.isoron.uhabits.gui.components
 
-data class Color(val paletteIndex: Int)
+import org.isoron.uhabits.gui.*
+
+interface Component {
+    fun draw(canvas: Canvas)
+}

core/src/commonMain/kotlin/org/isoron/uhabits/gui/components/HabitListHeader.kt

@@ -0,0 +1,58 @@
+/*
+ * 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.gui.components.HabitList
+
+import org.isoron.uhabits.gui.*
+import org.isoron.uhabits.gui.components.*
+import org.isoron.uhabits.utils.*
+
+class HabitListHeader(private val today: LocalDate,
+                      private val nButtons: Int,
+                      private val theme: Theme,
+                      private val fmt: LocalDateFormatter,
+                      private val calc: LocalDateCalculator) : Component {
+
+    override fun draw(canvas: Canvas) {
+        val width = canvas.getWidth()
+        val height = canvas.getHeight()
+        val buttonSize = theme.checkmarkButtonSize
+        canvas.setColor(theme.headerBackgroundColor)
+        canvas.fillRect(0.0, 0.0, width, height)
+
+        canvas.setColor(theme.headerBorderColor)
+        canvas.setStrokeWidth(0.5)
+        canvas.drawLine(0.0, height - 0.5, width, height - 0.5)
+
+        canvas.setColor(theme.headerTextColor)
+        canvas.setFont(Font.BOLD)
+        canvas.setTextSize(theme.smallTextSize)
+
+        repeat(nButtons) { index ->
+            val date = calc.minusDays(today, nButtons - index - 1)
+            val name = fmt.shortWeekdayName(date).toUpperCase()
+            val number = date.day.toString()
+
+            val x = width - (index + 1) * buttonSize + buttonSize / 2
+            val y = height / 2
+            canvas.drawText(name, x, y - theme.smallTextSize * 0.6)
+            canvas.drawText(number, x, y + theme.smallTextSize * 0.6)
+        }
+    }
+}

core/src/commonMain/kotlin/org/isoron/uhabits/gui/components/NumberButton.kt

@@ -0,0 +1,72 @@
+/*
+ * 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.gui.components.HabitList
+
+import org.isoron.uhabits.gui.*
+import org.isoron.uhabits.gui.components.*
+import org.isoron.uhabits.utils.*
+import kotlin.math.*
+
+fun Double.toShortString(): String = when {
+    this >= 1e9 -> sprintf("%.1fG", this / 1e9)
+    this >= 1e8 -> sprintf("%.0fM", this / 1e6)
+    this >= 1e7 -> sprintf("%.1fM", this / 1e6)
+    this >= 1e6 -> sprintf("%.1fM", this / 1e6)
+    this >= 1e5 -> sprintf("%.0fk", this / 1e3)
+    this >= 1e4 -> sprintf("%.1fk", this / 1e3)
+    this >= 1e3 -> sprintf("%.1fk", this / 1e3)
+    this >= 1e2 -> sprintf("%.0f", this)
+    this >= 1e1 -> when {
+        round(this) == this -> sprintf("%.0f", this)
+        else -> sprintf("%.1f", this)
+    }
+    else -> when {
+        round(this) == this -> sprintf("%.0f", this)
+        round(this * 10) == this * 10 -> sprintf("%.1f", this)
+        else -> sprintf("%.2f", this)
+    }
+}
+
+class NumberButton(val color: Color,
+                   val value: Double,
+                   val threshold: Double,
+                   val units: String,
+                   val theme: Theme) : Component {
+
+    override fun draw(canvas: Canvas) {
+        val width = canvas.getWidth()
+        val height = canvas.getHeight()
+        val em = theme.smallTextSize
+
+        canvas.setColor(when {
+                            value >= threshold -> color
+                            value >= 0.01 -> theme.mediumContrastTextColor
+                            else -> theme.lowContrastTextColor
+                        })
+
+        canvas.setTextSize(theme.regularTextSize)
+        canvas.setFont(Font.BOLD)
+        canvas.drawText(value.toShortString(), width / 2, height / 2 - 0.6 * em)
+
+        canvas.setTextSize(theme.smallTextSize)
+        canvas.setFont(Font.REGULAR)
+        canvas.drawText(units, width / 2, height / 2 + 0.6 * em)
+    }
+}

core/src/commonMain/kotlin/org/isoron/uhabits/gui/components/Ring.kt

@@ -0,0 +1,53 @@
+/*
+ * 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.gui.components
+
+import org.isoron.uhabits.gui.*
+import org.isoron.uhabits.utils.*
+import kotlin.math.*
+
+class Ring(val color: Color,
+           val percentage: Double,
+           val thickness: Double,
+           val radius: Double,
+           val theme: Theme,
+           val label: Boolean = false) : Component {
+
+    override fun draw(canvas: Canvas) {
+        val width = canvas.getWidth()
+        val height = canvas.getHeight()
+        val angle = 360.0 * max(0.0, min(360.0, percentage))
+
+        canvas.setColor(theme.lowContrastTextColor)
+        canvas.fillCircle(width/2, height/2, radius)
+
+        canvas.setColor(color)
+        canvas.fillArc(width/2, height/2, radius, 90.0, -angle)
+
+        canvas.setColor(theme.cardBackgroundColor)
+        canvas.fillCircle(width/2, height/2, radius - thickness)
+
+        if(label) {
+            canvas.setColor(color)
+            canvas.setTextSize(radius * 0.4)
+            canvas.drawText(sprintf("%.0f%%", percentage*100), width/2, height/2)
+        }
+    }
+}

core/src/commonMain/kotlin/org/isoron/uhabits/models/Checkmark.kt

@@ -19,5 +19,7 @@
 
 package org.isoron.uhabits.models
 
+import org.isoron.uhabits.utils.*
+
 data class Checkmark(var timestamp: Timestamp,
-                     var value: Int)
+                     var value: Int)

core/src/commonMain/kotlin/org/isoron/uhabits/models/Habit.kt

@@ -19,11 +19,13 @@
 
 package org.isoron.uhabits.models
 
+import org.isoron.uhabits.gui.*
+
 data class Habit(var id: Int,
                  var name: String,
                  var description: String,
                  var frequency: Frequency,
-                 var color: Color,
+                 var color: PaletteColor,
                  var isArchived: Boolean,
                  var position: Int,
                  var unit: String,

core/src/commonMain/kotlin/org/isoron/uhabits/models/HabitRepository.kt

@@ -19,6 +19,7 @@
 
 package org.isoron.uhabits.models
 
+import org.isoron.uhabits.gui.*
 import org.isoron.uhabits.utils.Database
 import org.isoron.uhabits.utils.PreparedStatement
 import org.isoron.uhabits.utils.StepResult
@@ -69,7 +70,7 @@ class HabitRepository(var db: Database) {
                      name = stmt.getText(1),
                      description = stmt.getText(2),
                      frequency = Frequency(stmt.getInt(3), stmt.getInt(4)),
-                     color = Color(stmt.getInt(5)),
+                     color = PaletteColor(stmt.getInt(5)),
                      isArchived = stmt.getInt(6) != 0,
                      position = stmt.getInt(7),
                      unit = stmt.getText(8),
@@ -83,7 +84,7 @@ class HabitRepository(var db: Database) {
         statement.bindText(2, habit.description)
         statement.bindInt(3, habit.frequency.numerator)
         statement.bindInt(4, habit.frequency.denominator)
-        statement.bindInt(5, habit.color.paletteIndex)
+        statement.bindInt(5, habit.color.index)
         statement.bindInt(6, if (habit.isArchived) 1 else 0)
         statement.bindInt(7, habit.position)
         statement.bindText(8, habit.unit)

core/src/commonMain/kotlin/org/isoron/uhabits/utils/Dates.kt

@@ -0,0 +1,42 @@
+/*
+ * 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.utils
+
+data class Timestamp(val unixTime: Long)
+
+data class LocalDate(val year: Int,
+                     val month: Int,
+                     val day: Int) {
+    init {
+        if ((month <= 0) or (month >= 13)) throw(IllegalArgumentException())
+        if ((day <= 0) or (day >= 32)) throw(IllegalArgumentException())
+    }
+}
+
+interface LocalDateCalculator {
+    fun plusDays(date: LocalDate, days: Int): LocalDate
+    fun minusDays(date: LocalDate, days: Int): LocalDate {
+        return plusDays(date, -days)
+    }
+}
+
+interface LocalDateFormatter {
+    fun shortWeekdayName(date: LocalDate): String
+}

core/src/iosMain/kotlin/org/isoron/uhabits/utils/IosFiles.kt

@@ -1,55 +0,0 @@
-/*
- * 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.utils
-
-import platform.Foundation.*
-
-class IosResourceFile(val path: String) : ResourceFile {
-    private val fileManager = NSFileManager.defaultManager()
-    override fun readLines(): List<String> {
-        val contents = NSString.stringWithContentsOfFile(path) as NSString
-        return contents.componentsSeparatedByCharactersInSet(NSCharacterSet.newlineCharacterSet()) as List<String>
-    }
-}
-
-class IosUserFile(val path: String) : UserFile {
-    override fun exists(): Boolean {
-        return NSFileManager.defaultManager().fileExistsAtPath(path)
-    }
-
-    override fun delete() {
-        NSFileManager.defaultManager().removeItemAtPath(path, null)
-    }
-}
-
-class IosFileOpener : FileOpener {
-    override fun openResourceFile(filename: String): ResourceFile {
-        val root = NSBundle.mainBundle.resourcePath!!
-        return IosResourceFile("$root/$filename")
-    }
-
-    override fun openUserFile(filename: String): UserFile {
-        val manager = NSFileManager.defaultManager()
-        val root = manager.URLForDirectory(NSDocumentDirectory,
-                                           NSUserDomainMask,
-                                           null, false, null)!!.path
-        return IosUserFile("$root/$filename")
-    }
-}

core/src/jvmMain/kotlin/org/isoron/uhabits/gui/JavaCanvas.kt

@@ -0,0 +1,144 @@
+/*
+ * 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.gui
+
+import org.isoron.uhabits.utils.*
+import java.awt.*
+import java.awt.RenderingHints.*
+import java.awt.font.*
+import java.lang.Math.*
+import kotlin.math.*
+
+fun createFont(path: String): java.awt.Font {
+    return java.awt.Font.createFont(0,
+                                    (JavaFileOpener().openResourceFile(path) as JavaResourceFile).stream())
+}
+
+private val ROBOTO_REGULAR_FONT = createFont("fonts/Roboto-Regular.ttf")
+private val ROBOTO_BOLD_FONT = createFont("fonts/Roboto-Bold.ttf")
+private val FONT_AWESOME_FONT = createFont("fonts/FontAwesome.ttf")
+
+class JavaCanvas(val g2d: Graphics2D,
+                 val widthPx: Int,
+                 val heightPx: Int,
+                 val pixelScale: Double = 2.0) : Canvas {
+    private val frc = FontRenderContext(null, true, true)
+    private var fontSize = 12.0
+    private var font = Font.REGULAR
+
+    init {
+        g2d.setRenderingHint(KEY_ANTIALIASING, VALUE_ANTIALIAS_ON);
+        g2d.setRenderingHint(KEY_TEXT_ANTIALIASING, VALUE_TEXT_ANTIALIAS_ON);
+        g2d.setRenderingHint(KEY_FRACTIONALMETRICS, VALUE_FRACTIONALMETRICS_ON);
+        updateFont()
+    }
+
+    private fun toPixel(x: Double): Int {
+        return (pixelScale * x).toInt()
+    }
+
+    private fun toDp(x: Int): Double {
+        return x / pixelScale
+    }
+
+    override fun setColor(color: Color) {
+        g2d.color = java.awt.Color(color.red.toFloat(),
+                                   color.green.toFloat(),
+                                   color.blue.toFloat())
+    }
+
+    override fun drawLine(x1: Double, y1: Double, x2: Double, y2: Double) {
+        g2d.drawLine(toPixel(x1), toPixel(y1), toPixel(x2), toPixel(y2))
+    }
+
+    override fun drawText(text: String, x: Double, y: Double) {
+        val bounds = g2d.font.getStringBounds(text, frc)
+        val bWidth = bounds.width.roundToInt()
+        val bHeight = bounds.height.roundToInt()
+        val bx = bounds.x.roundToInt()
+        val by = bounds.y.roundToInt()
+
+        g2d.drawString(text,
+                       toPixel(x) - bx - bWidth / 2,
+                       toPixel(y) - by - bHeight / 2)
+    }
+
+    override fun fillRect(x: Double, y: Double, width: Double, height: Double) {
+        g2d.fillRect(toPixel(x), toPixel(y), toPixel(width), toPixel(height))
+    }
+
+    override fun drawRect(x: Double, y: Double, width: Double, height: Double) {
+        g2d.drawRect(toPixel(x), toPixel(y), toPixel(width), toPixel(height))
+    }
+
+    override fun getHeight(): Double {
+        return toDp(heightPx)
+    }
+
+    override fun getWidth(): Double {
+        return toDp(widthPx)
+    }
+
+
+    override fun setFont(font: Font) {
+        this.font = font
+        updateFont()
+    }
+
+    override fun setTextSize(size: Double) {
+        fontSize = size
+        updateFont()
+    }
+
+    override fun setStrokeWidth(size: Double) {
+        g2d.setStroke(BasicStroke(size.toFloat()))
+    }
+
+    private fun updateFont() {
+        val size = (fontSize * pixelScale).toFloat()
+        g2d.font = when (font) {
+            Font.REGULAR -> ROBOTO_REGULAR_FONT.deriveFont(size)
+            Font.BOLD -> ROBOTO_BOLD_FONT.deriveFont(size)
+            Font.FONT_AWESOME -> FONT_AWESOME_FONT.deriveFont(size)
+        }
+    }
+
+    override fun fillCircle(centerX: Double, centerY: Double, radius: Double) {
+        g2d.fillOval(toPixel(centerX - radius),
+                     toPixel(centerY - radius),
+                     toPixel(radius * 2),
+                     toPixel(radius * 2))
+    }
+
+    override fun fillArc(centerX: Double,
+                         centerY: Double,
+                         radius: Double,
+                         startAngle: Double,
+                         swipeAngle: Double) {
+
+        g2d.fillArc(toPixel(centerX - radius),
+                    toPixel(centerY - radius),
+                    toPixel(radius * 2),
+                    toPixel(radius * 2),
+                    startAngle.roundToInt(),
+                    swipeAngle.roundToInt())
+    }
+
+}

core/src/jvmMain/kotlin/org/isoron/uhabits/utils/JavaDates.kt

@@ -0,0 +1,40 @@
+/*
+ * 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.utils
+
+import java.util.*
+import java.util.Calendar.*
+
+class JavaLocalDateFormatter(private val locale: Locale) : LocalDateFormatter {
+    override fun shortWeekdayName(date: LocalDate): String {
+        val d = GregorianCalendar(date.year, date.month - 1, date.day)
+        return d.getDisplayName(DAY_OF_WEEK, SHORT, locale);
+    }
+}
+
+class JavaLocalDateCalculator : LocalDateCalculator {
+    override fun plusDays(date: LocalDate, days: Int): LocalDate {
+        val d = GregorianCalendar(date.year, date.month - 1, date.day)
+        d.add(Calendar.DAY_OF_MONTH, days)
+        return LocalDate(d.get(Calendar.YEAR),
+                         d.get(Calendar.MONTH) + 1,
+                         d.get(Calendar.DAY_OF_MONTH))
+    }
+}

core/src/jvmMain/kotlin/org/isoron/uhabits/utils/JavaFiles.kt

@@ -19,6 +19,7 @@
 
 package org.isoron.uhabits.utils
 
+import java.io.*
 import java.nio.file.Files
 import java.nio.file.Path
 import java.nio.file.Paths
@@ -27,6 +28,10 @@ class JavaResourceFile(private val path: Path) : ResourceFile {
     override fun readLines(): List<String> {
         return Files.readAllLines(path)
     }
+
+    fun stream(): InputStream {
+        return Files.newInputStream(path)
+    }
 }
 
 class JavaUserFile(val path: Path) : UserFile {

core/src/jvmTest/kotlin/org/isoron/uhabits/Base.kt

@@ -0,0 +1,99 @@
+/*
+ * 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
+
+import junit.framework.TestCase.*
+import org.isoron.uhabits.gui.*
+import org.isoron.uhabits.gui.components.*
+import org.isoron.uhabits.utils.*
+import org.junit.Before
+import java.awt.image.*
+import java.io.*
+import java.lang.RuntimeException
+import javax.imageio.*
+import kotlin.math.*
+
+open class BaseTest {
+    val fileOpener = JavaFileOpener()
+    val log = StandardLog()
+    val databaseOpener = JavaDatabaseOpener(log)
+    lateinit var db: Database
+
+    @Before
+    open fun setUp() {
+        val dbFile = fileOpener.openUserFile("test.sqlite3")
+        if (dbFile.exists()) dbFile.delete()
+        db = databaseOpener.open(dbFile)
+        db.migrateTo(LOOP_DATABASE_VERSION, fileOpener, log)
+    }
+}
+
+open class BaseViewTest {
+    val theme = LightTheme()
+    fun distance(actual: BufferedImage,
+                         expected: BufferedImage): Double {
+
+        if (actual.width != expected.width) return Double.POSITIVE_INFINITY
+        if (actual.height != expected.height) return Double.POSITIVE_INFINITY
+
+        var distance = 0.0;
+        for (x in 0 until actual.width) {
+            for (y in 0 until actual.height) {
+                val p1 = Color(actual.getRGB(x, y))
+                val p2 = Color(expected.getRGB(x, y))
+                distance += abs(p1.red - p2.red)
+                distance += abs(p1.green - p2.green)
+                distance += abs(p1.blue - p2.blue)
+            }
+        }
+
+        return 255 * distance / (actual.width * actual.height)
+    }
+
+    fun assertRenders(width: Int,
+                      height: Int,
+                      expectedPath: String,
+                      component: Component,
+                      threshold: Double = 1.0) {
+        val actual = BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB)
+        val canvas = JavaCanvas(actual.createGraphics(), width, height)
+        val expectedFile: JavaResourceFile
+        val actualPath = "/tmp/${expectedPath}"
+
+        component.draw(canvas)
+        try {
+            expectedFile = JavaFileOpener().openResourceFile(expectedPath) as JavaResourceFile
+        } catch(e: RuntimeException) {
+            File(actualPath).parentFile.mkdirs()
+            ImageIO.write(actual, "png", File(actualPath))
+            fail("Expected file is missing. Actual render saved to $actualPath")
+            return
+        }
+
+        val expected = ImageIO.read(expectedFile.stream())
+        val d = distance(actual, expected)
+        if (d >= threshold) {
+            File(actualPath).parentFile.mkdirs()
+            ImageIO.write(actual, "png", File(actualPath))
+            ImageIO.write(expected, "png", File(actualPath.replace(".png", ".expected.png")))
+            fail("Images differ (distance=${d}). Actual rendered saved to ${actualPath}.")
+        }
+    }
+}

core/src/jvmTest/kotlin/org/isoron/uhabits/gui/JavaCanvasTest.kt

@@ -0,0 +1,69 @@
+/*
+ * 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.gui
+
+import org.junit.*
+import java.awt.image.*
+import java.io.*
+import javax.imageio.*
+
+
+class JavaCanvasTest {
+    @Test
+    fun testDrawing() {
+        val image = BufferedImage(500, 400, BufferedImage.TYPE_INT_RGB)
+        val canvas = JavaCanvas(image.createGraphics(), 500, 400, pixelScale=1.0)
+
+        canvas.setColor(Color(0x303030))
+        canvas.fillRect(0.0, 0.0, 500.0, 400.0)
+
+        canvas.setColor(Color(0x606060))
+        canvas.setStrokeWidth(25.0)
+        canvas.drawRect(100.0, 100.0, 300.0, 200.0)
+
+        canvas.setColor(Color(0xFFFF00))
+        canvas.setStrokeWidth(1.0)
+        canvas.drawRect(0.0, 0.0, 100.0, 100.0)
+        canvas.fillCircle(50.0, 50.0, 30.0)
+        canvas.drawRect(0.0, 100.0, 100.0, 100.0)
+        canvas.fillArc(50.0, 150.0, 30.0, 90.0, 135.0)
+        canvas.drawRect(0.0, 200.0, 100.0, 100.0)
+        canvas.fillArc(50.0, 250.0, 30.0, 90.0, -135.0)
+        canvas.drawRect(0.0, 300.0, 100.0, 100.0)
+        canvas.fillArc(50.0, 350.0, 30.0, 45.0, 90.0)
+
+        canvas.setColor(Color(0xFF0000))
+        canvas.setStrokeWidth(2.0)
+        canvas.drawLine(0.0, 0.0, 500.0, 400.0)
+        canvas.drawLine(500.0, 0.0, 0.0, 400.0)
+
+        canvas.setTextSize(50.0)
+        canvas.setColor(Color(0x00FF00))
+        canvas.drawText("Test", 250.0, 200.0)
+
+        canvas.setFont(Font.BOLD)
+        canvas.drawText("Test", 250.0, 100.0)
+
+        canvas.setFont(Font.FONT_AWESOME)
+        canvas.drawText(FontAwesome.CHECK, 250.0, 300.0)
+
+        ImageIO.write(image, "png", File("/tmp/JavaCanvasTest.png"))
+    }
+}

core/src/jvmTest/kotlin/org/isoron/uhabits/gui/components/CheckmarkButtonTest.kt

@@ -0,0 +1,46 @@
+/*
+ * 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.gui.components
+
+import org.isoron.uhabits.*
+import org.isoron.uhabits.gui.components.HabitList.*
+import org.junit.*
+
+class CheckmarkButtonTest : BaseViewTest() {
+    val base = "components/CheckmarkButton"
+
+    @Test
+    fun testDrawExplicit() {
+        val component = CheckmarkButton(2, theme.color(8), theme)
+        assertRenders(96, 96, "$base/explicit.png", component)
+    }
+
+    @Test
+    fun testDrawImplicit() {
+        val component = CheckmarkButton(1, theme.color(8), theme)
+        assertRenders(96, 96, "$base/implicit.png", component)
+    }
+
+    @Test
+    fun testDrawUnchecked() {
+        val component = CheckmarkButton(0, theme.color(8), theme)
+        assertRenders(96, 96, "$base/unchecked.png", component)
+    }
+}

core/src/jvmTest/kotlin/org/isoron/uhabits/gui/components/HabitListHeaderTest.kt

@@ -0,0 +1,41 @@
+/*
+ * 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.gui.components
+
+import org.isoron.uhabits.*
+import org.isoron.uhabits.gui.components.HabitList.*
+import org.isoron.uhabits.utils.*
+import org.isoron.uhabits.utils.LocalDate
+import org.junit.*
+import java.util.*
+
+class HabitListHeaderTest : BaseViewTest() {
+    @Test
+    fun testDraw() {
+        val header = HabitListHeader(LocalDate(2019, 3, 25),
+                                     5,
+                                     theme,
+                                     JavaLocalDateFormatter(Locale.US),
+                                     JavaLocalDateCalculator())
+        assertRenders(1200, 96,
+                      "components/HabitListHeader/light.png",
+                      header)
+    }
+}

core/src/jvmTest/kotlin/org/isoron/uhabits/gui/components/NumberButtonTest.kt

@@ -0,0 +1,66 @@
+/*
+ * 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.gui.components
+
+import org.hamcrest.CoreMatchers.*
+import org.isoron.uhabits.*
+import org.isoron.uhabits.gui.components.HabitList.*
+import org.junit.*
+import org.junit.Assert.*
+
+class NumberButtonTest : BaseViewTest() {
+    val base = "components/NumberButton/"
+
+    @Test
+    fun testFormatValue() {
+        assertThat(0.1235.toShortString(), equalTo("0.12"))
+        assertThat(0.1000.toShortString(), equalTo("0.1"))
+        assertThat(5.0.toShortString(), equalTo("5"))
+        assertThat(5.25.toShortString(), equalTo("5.25"))
+        assertThat(12.3456.toShortString(), equalTo("12.3"))
+        assertThat(123.123.toShortString(), equalTo("123"))
+        assertThat(321.2.toShortString(), equalTo("321"))
+        assertThat(4321.2.toShortString(), equalTo("4.3k"))
+        assertThat(54321.2.toShortString(), equalTo("54.3k"))
+        assertThat(654321.2.toShortString(), equalTo("654k"))
+        assertThat(7654321.2.toShortString(), equalTo("7.7M"))
+        assertThat(87654321.2.toShortString(), equalTo("87.7M"))
+        assertThat(987654321.2.toShortString(), equalTo("988M"))
+        assertThat(1987654321.2.toShortString(), equalTo("2.0G"))
+    }
+
+    @Test
+    fun testRenderAbove() {
+        val btn = NumberButton(theme.color(8), 500.0, 100.0, "steps", theme)
+        assertRenders(96, 96, "$base/render_above.png", btn)
+    }
+
+    @Test
+    fun testRenderBelow() {
+        val btn = NumberButton(theme.color(8), 99.0, 100.0, "steps", theme)
+        assertRenders(96, 96, "$base/render_below.png", btn)
+    }
+
+    @Test
+    fun testRenderZero() {
+        val btn = NumberButton(theme.color(8), 0.0, 100.0, "steps", theme)
+        assertRenders(96, 96, "$base/render_zero.png", btn)
+    }
+}

core/src/jvmTest/kotlin/org/isoron/uhabits/gui/components/RingTest.kt

@@ -0,0 +1,39 @@
+/*
+ * 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.gui.components
+
+import org.isoron.uhabits.*
+import org.isoron.uhabits.gui.components.HabitList.*
+import org.junit.*
+
+class RingTest : BaseViewTest() {
+    val base = "components/Ring"
+
+    @Test
+    fun testDraw() {
+        val component = Ring(theme.color(8),
+                             percentage = 0.30,
+                             thickness = 5.0,
+                             radius = 30.0,
+                             theme = theme,
+                             label = true)
+        assertRenders(120, 120, "$base/draw1.png", component)
+    }
+}

core/src/jvmTest/kotlin/org/isoron/uhabits/models/HabitRepositoryTest.kt

@@ -21,6 +21,7 @@ package org.isoron.uhabits.models
 
 import junit.framework.Assert.assertEquals
 import org.isoron.uhabits.BaseTest
+import org.isoron.uhabits.gui.*
 import org.junit.Before
 import org.junit.Test
 
@@ -39,7 +40,7 @@ class HabitRepositoryTest : BaseTest() {
                           name = "Wake up early",
                           description = "Did you wake up before 6am?",
                           frequency = Frequency(1, 1),
-                          color = Color(3),
+                          color = PaletteColor(3),
                           isArchived = false,
                           position = 0,
                           unit = "",
@@ -50,7 +51,7 @@ class HabitRepositoryTest : BaseTest() {
                           name = "Exercise",
                           description = "Did you exercise for at least 20 minutes?",
                           frequency = Frequency(1, 2),
-                          color = Color(4),
+                          color = PaletteColor(4),
                           isArchived = false,
                           position = 1,
                           unit = "",
@@ -61,7 +62,7 @@ class HabitRepositoryTest : BaseTest() {
                           name = "Learn Japanese",
                           description = "Did you study Japanese today?",
                           frequency = Frequency(1, 1),
-                          color = Color(3),
+                          color = PaletteColor(3),
                           isArchived = false,
                           position = 2,
                           unit = "",

core/src/jvmTest/kotlin/org/isoron/uhabits/utils/JavaDatesTest.kt

@@ -0,0 +1,50 @@
+/*
+ * 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.utils
+
+import junit.framework.TestCase.*
+import org.junit.*
+import java.util.*
+
+
+class JavaDatesTest {
+    val calc = JavaLocalDateCalculator()
+
+    @Test
+    fun plusMinusDays() {
+        val today = LocalDate(2019, 3, 25)
+        assertEquals(calc.minusDays(today, 28), LocalDate(2019, 2, 25))
+        assertEquals(calc.plusDays(today, 7), LocalDate(2019, 4, 1))
+        assertEquals(calc.plusDays(today, 42), LocalDate(2019, 5, 6))
+    }
+
+    @Test
+    fun shortMonthName() {
+        var fmt = JavaLocalDateFormatter(Locale.US)
+        assertEquals(fmt.shortWeekdayName(LocalDate(2019, 3, 25)), "Mon")
+        assertEquals(fmt.shortWeekdayName(LocalDate(2019, 4, 4)), "Thu")
+        assertEquals(fmt.shortWeekdayName(LocalDate(2019, 5, 12)), "Sun")
+
+        fmt = JavaLocalDateFormatter(Locale.JAPAN)
+        assertEquals(fmt.shortWeekdayName(LocalDate(2019, 3, 25)), "月")
+        assertEquals(fmt.shortWeekdayName(LocalDate(2019, 4, 4)), "木")
+        assertEquals(fmt.shortWeekdayName(LocalDate(2019, 5, 12)), "日")
+    }
+}