Add week number feature (alamkanak#146)

* Add week number feature

* Fix issue where week number didn't consider manually set first day of week

Author: thellmund

core/src/main/java/com/alamkanak/weekview/CalendarExtensions.kt

@@ -43,6 +43,9 @@ internal val Calendar.dayOfWeek: Int
 internal val Calendar.dayOfMonth: Int
     get() = get(Calendar.DAY_OF_MONTH)
 
+internal val Calendar.weekOfYear: Int
+    get() = get(Calendar.WEEK_OF_YEAR)
+
 internal val Calendar.month: Int
     get() = get(Calendar.MONTH)
 
@@ -191,8 +194,10 @@ internal fun firstDayOfYear(): Calendar {
     }
 }
 
-internal fun getDateRange(start: Int, end: Int): List<Calendar> {
-    return (start..end).map { today() + Days(it - 1) }
+internal fun WeekViewConfigWrapper.createDateRange(start: Int, end: Int): List<Calendar> {
+    val firstDate = today()
+    firstDate.firstDayOfWeek = firstDayOfWeek
+    return (start..end).map { firstDate + Days(it - 1) }
 }
 
 internal val Calendar.isWeekend: Boolean

core/src/main/java/com/alamkanak/weekview/DrawingContext.kt

@@ -29,7 +29,7 @@ internal class DrawingContext(
         val modifiedEnd = if (isNotScrolling) end - 1 else end
 
         dateRange.clear()
-        dateRange += getDateRange(start, modifiedEnd)
+        dateRange += config.createDateRange(start, modifiedEnd)
 
         updateStartPixels()
 

core/src/main/java/com/alamkanak/weekview/HeaderRowDrawer.kt

@@ -1,6 +1,10 @@
 package com.alamkanak.weekview
 
 import android.graphics.Canvas
+import android.graphics.Paint
+import android.graphics.Rect
+import android.graphics.RectF
+import kotlin.math.roundToInt
 
 internal class HeaderRowDrawer<T : Any>(
     private val view: WeekView<T>,
@@ -14,9 +18,50 @@ internal class HeaderRowDrawer<T : Any>(
         val width = view.width.toFloat()
         canvas.drawRect(0f, 0f, width, config.headerHeight, config.headerBackgroundPaint)
 
+        if (config.showWeekNumber) {
+            canvas.drawWeekNumber(drawingContext)
+        }
+
         if (config.showHeaderRowBottomLine) {
-            val top = config.headerHeight - config.headerRowBottomLineWidth
-            canvas.drawLine(0f, top, width, top, config.headerRowBottomLinePaint)
+            val y = config.headerHeight - config.headerRowBottomLineWidth
+            canvas.drawLine(0f, y, width, y, config.headerRowBottomLinePaint)
         }
     }
+
+    private fun Canvas.drawWeekNumber(drawingContext: DrawingContext) {
+        val weekNumber = drawingContext.dateRange.first().weekOfYear.toString()
+
+        val bounds = config.weekNumberBounds
+        val textPaint = config.weekNumberTextPaint
+
+        val textHeight = textPaint.textHeight
+        val textOffset = (textHeight / 2f).roundToInt() - textPaint.descent().roundToInt()
+
+        val width = textPaint.getTextBounds("52").width() * 2.5f
+        val height = textHeight * 1.5f
+
+        val backgroundRect = RectF(
+            bounds.centerX() - width / 2f,
+            bounds.centerY() - height / 2f,
+            bounds.centerX() + width / 2f,
+            bounds.centerY() + height / 2f
+        )
+
+        drawRect(bounds, config.headerBackgroundPaint)
+
+        val backgroundPaint = config.weekNumberBackgroundPaint
+        val radius = config.weekNumberBackgroundCornerRadius.toFloat()
+        drawRoundRect(backgroundRect, radius, radius, backgroundPaint)
+
+        drawText(weekNumber, bounds.centerX(), bounds.centerY() + textOffset, textPaint)
+    }
+}
+
+internal val Paint.textHeight: Int
+    get() = (descent() - ascent()).roundToInt()
+
+internal fun Paint.getTextBounds(text: String): Rect {
+    val rect = Rect()
+    getTextBounds(text, 0, text.length, rect)
+    return rect
 }

core/src/main/java/com/alamkanak/weekview/WeekViewConfig.kt

@@ -45,6 +45,13 @@ internal class WeekViewConfig(
     var todayHeaderTextColor: Int = 0
     var singleLineHeader: Boolean = false
 
+    // Week number
+    var showWeekNumber: Boolean = false
+    var weekNumberTextColor: Int = 0
+    var weekNumberTextSize: Int = 0
+    var weekNumberBackgroundColor: Int = 0
+    var weekNumberBackgroundCornerRadius: Int = 0
+
     // Event chips
     var eventCornerRadius: Int = 0
     var eventTextSize: Int = 0
@@ -158,6 +165,13 @@ internal class WeekViewConfig(
             todayHeaderTextColor = getColor(R.styleable.WeekView_todayHeaderTextColor, Defaults.HIGHLIGHT_COLOR)
             singleLineHeader = getBoolean(R.styleable.WeekView_singleLineHeader, true)
 
+            // Week number
+            showWeekNumber = a.getBoolean(R.styleable.WeekView_showWeekNumber, false)
+            weekNumberTextColor = a.getColor(R.styleable.WeekView_weekNumberTextColor, Color.WHITE)
+            weekNumberTextSize = a.getDimensionPixelSize(R.styleable.WeekView_weekNumberTextSize, Defaults.textSize(context))
+            weekNumberBackgroundColor = a.getColor(R.styleable.WeekView_weekNumberBackgroundColor, Color.LTGRAY)
+            weekNumberBackgroundCornerRadius = a.getDimensionPixelSize(R.styleable.WeekView_weekNumberBackgroundCornerRadius, 0)
+
             // Event chips
             eventCornerRadius = getDimensionPixelSize(R.styleable.WeekView_eventCornerRadius, 0)
             eventTextSize = getDimensionPixelSize(R.styleable.WeekView_eventTextSize, Defaults.textSize(context))

core/src/main/java/com/alamkanak/weekview/WeekViewConfigWrapper.kt

@@ -3,6 +3,7 @@ package com.alamkanak.weekview
 import android.graphics.Paint
 import android.graphics.PointF
 import android.graphics.Rect
+import android.graphics.RectF
 import android.graphics.Typeface
 import android.text.TextPaint
 import com.alamkanak.weekview.Constants.UNINITIALIZED
@@ -329,6 +330,60 @@ internal class WeekViewConfigWrapper(
     val headerRowBottomLineWidth: Float
         get() = if (showHeaderRowBottomLine) headerRowBottomLinePaint.strokeWidth else 0f
 
+    var showWeekNumber: Boolean
+        get() = config.showWeekNumber
+        set(value) {
+            config.showWeekNumber = value
+        }
+
+    var weekNumberTextColor: Int
+        get() = config.weekNumberTextColor
+        set(value) {
+            config.weekNumberTextColor = value
+        }
+    var weekNumberTextSize: Int
+        get() = config.weekNumberTextSize
+        set(value) {
+            config.weekNumberTextSize = value
+        }
+    var weekNumberBackgroundColor: Int
+        get() = config.weekNumberBackgroundColor
+        set(value) {
+            config.weekNumberBackgroundColor = value
+        }
+    var weekNumberBackgroundCornerRadius: Int
+        get() = config.weekNumberBackgroundCornerRadius
+        set(value) {
+            config.weekNumberBackgroundCornerRadius = value
+        }
+
+    private val _weekNumberBounds: RectF = RectF()
+
+    val weekNumberBounds: RectF
+        get() = _weekNumberBounds.apply {
+            left = 0f
+            top = 0f
+            right = timeColumnWidth
+            bottom = headerHeight
+        }
+
+    private val _weekNumberTextPaint: Paint = TextPaint(Paint.ANTI_ALIAS_FLAG)
+
+    val weekNumberTextPaint: Paint
+        get() = _weekNumberTextPaint.apply {
+            color = weekNumberTextColor
+            textAlign = Paint.Align.CENTER
+            textSize = weekNumberTextSize.toFloat()
+            typeface = this@WeekViewConfigWrapper.typeface
+        }
+
+    private val _weekNumberBackgroundPaint: Paint = Paint(Paint.ANTI_ALIAS_FLAG)
+
+    val weekNumberBackgroundPaint: Paint
+        get() = _weekNumberBackgroundPaint.apply {
+            color = weekNumberBackgroundColor
+        }
+
     val singleLineHeader: Boolean
         get() = config.singleLineHeader
 

core/src/main/res/values/attrs.xml

@@ -49,6 +49,13 @@
         <attr name="todayHeaderTextColor" format="color" />
         <attr name="singleLineHeader" format="boolean" />
 
+        <!-- Week number -->
+        <attr name="showWeekNumber" format="boolean" />
+        <attr name="weekNumberTextColor" format="color" />
+        <attr name="weekNumberTextSize" format="dimension" />
+        <attr name="weekNumberBackgroundColor" format="color" />
+        <attr name="weekNumberBackgroundCornerRadius" format="dimension" />
+
         <!-- Event chips -->
         <attr name="eventCornerRadius" format="dimension" />
         <attr name="eventTextSize" format="dimension" />

sample/src/main/res/layout/activity_basic.xml

@@ -34,13 +34,17 @@
         app:showNowLine="true"
         app:showNowLineDot="true"
         app:showTimeColumnSeparator="true"
+        app:showWeekNumber="true"
         app:singleDayHorizontalMargin="8dp"
         app:timeColumnBackgroundColor="#ffffffff"
         app:timeColumnPadding="8dp"
         app:timeColumnSeparatorColor="@color/header_bottom_line"
         app:timeColumnSeparatorStrokeWidth="1dp"
         app:timeColumnTextColor="@color/toolbar_text"
         app:timeColumnTextSize="12sp"
-        app:todayHeaderTextColor="@color/accent" />
+        app:todayHeaderTextColor="@color/accent"
+        app:weekNumberBackgroundColor="@color/dark_gray"
+        app:weekNumberBackgroundCornerRadius="@dimen/corner_radius"
+        app:weekNumberTextColor="@android:color/white" />
 
 </LinearLayout>

sample/src/main/res/values/colors.xml

@@ -9,4 +9,5 @@
     <color name="toolbar_text">#8f000000</color>
     <color name="accent">#2789e4</color>
     <color name="divider">#E2E2E2</color>
+    <color name="dark_gray">#aeaeae</color>
 </resources>

sample/src/main/res/values/dimens.xml

@@ -3,4 +3,5 @@
     <dimen name="default_space">16dp</dimen>
     <dimen name="border_width">1dp</dimen>
     <dimen name="no_border_width">0dp</dimen>
+    <dimen name="corner_radius">8dp</dimen>
 </resources>