Add eye dropper

app/src/main/kotlin/com/simplemobiletools/draw/pro/activities/MainActivity.kt

@@ -13,8 +13,8 @@ import android.view.Menu
 import android.view.MenuItem
 import android.view.WindowManager
 import android.webkit.MimeTypeMap
-import android.widget.ImageView
 import android.widget.SeekBar
+import androidx.core.content.ContextCompat
 import androidx.print.PrintHelper
 import com.simplemobiletools.commons.dialogs.ColorPickerDialog
 import com.simplemobiletools.commons.dialogs.ConfirmationAdvancedDialog
@@ -30,6 +30,7 @@ import com.simplemobiletools.draw.pro.BuildConfig
 import com.simplemobiletools.draw.pro.R
 import com.simplemobiletools.draw.pro.dialogs.SaveImageDialog
 import com.simplemobiletools.draw.pro.extensions.config
+import com.simplemobiletools.draw.pro.helpers.EyeDropper
 import com.simplemobiletools.draw.pro.helpers.JPG
 import com.simplemobiletools.draw.pro.helpers.PNG
 import com.simplemobiletools.draw.pro.helpers.SVG
@@ -60,10 +61,17 @@ class MainActivity : SimpleActivity(), CanvasListener {
     private var savedPathsHash = 0L
     private var lastSavePromptTS = 0L
     private var isEraserOn = false
+    private var isEyeDropperOn = false
     private var isImageCaptureIntent = false
     private var isEditIntent = false
     private var lastBitmapPath = ""
 
+    private val eyeDropper by lazy {
+        EyeDropper(my_canvas) { selectedColor ->
+            setColor(selectedColor)
+        }
+    }
+
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_main)
@@ -88,6 +96,7 @@ class MainActivity : SimpleActivity(), CanvasListener {
             true
         }
         redo.setOnClickListener { my_canvas.redo() }
+        eye_dropper.setOnClickListener { eyeDropperClicked() }
 
         checkIntents()
         if (!isImageCaptureIntent) {
@@ -184,7 +193,8 @@ class MainActivity : SimpleActivity(), CanvasListener {
         val faqItems = arrayListOf(
             FAQItem(R.string.faq_2_title_commons, R.string.faq_2_text_commons),
             FAQItem(R.string.faq_6_title_commons, R.string.faq_6_text_commons),
-            FAQItem(R.string.faq_7_title_commons, R.string.faq_7_text_commons))
+            FAQItem(R.string.faq_7_title_commons, R.string.faq_7_text_commons)
+        )
 
         startAboutActivity(R.string.app_name, licenses, BuildConfig.VERSION_NAME, faqItems, false)
     }
@@ -317,7 +327,7 @@ class MainActivity : SimpleActivity(), CanvasListener {
     }
 
     private fun updateEraserState() {
-        eraser.setImageDrawable(resources.getDrawable(if (isEraserOn) R.drawable.ic_eraser_on else R.drawable.ic_eraser_off))
+        eraser.setImageDrawable(ContextCompat.getDrawable(this, if (isEraserOn) R.drawable.ic_eraser_on else R.drawable.ic_eraser_off))
         my_canvas.toggleEraser(isEraserOn)
     }
 
@@ -335,6 +345,16 @@ class MainActivity : SimpleActivity(), CanvasListener {
         }
     }
 
+    private fun eyeDropperClicked() {
+        isEyeDropperOn = !isEyeDropperOn
+        if (isEyeDropperOn) {
+            eyeDropper.start()
+        } else {
+            eyeDropper.stop()
+        }
+        eye_dropper.setImageDrawable(ContextCompat.getDrawable(this, if (isEyeDropperOn) R.drawable.ic_colorise_off_vector else R.drawable.ic_colorize_vector))
+    }
+
     private fun confirmImage() {
         when {
             isEditIntent -> {
@@ -496,6 +516,7 @@ class MainActivity : SimpleActivity(), CanvasListener {
         undo.applyColorFilter(contrastColor)
         eraser.applyColorFilter(contrastColor)
         redo.applyColorFilter(contrastColor)
+        eye_dropper.applyColorFilter(contrastColor)
         if (isBlackAndWhiteTheme()) {
             stroke_width_bar.setColors(0, contrastColor, 0)
         }

app/src/main/kotlin/com/simplemobiletools/draw/pro/helpers/EyeDropper.kt

@@ -0,0 +1,85 @@
+package com.simplemobiletools.draw.pro.helpers
+
+import android.graphics.Bitmap
+import android.graphics.Color
+import android.graphics.Matrix
+import android.graphics.drawable.BitmapDrawable
+import android.view.View
+import android.view.View.DRAWING_CACHE_QUALITY_LOW
+import android.widget.ImageView
+
+
+// forked from  https://github.com/Madrapps/EyeDropper
+class EyeDropper(private val view: View, private val onColorSelected: ((Int) -> Unit)) {
+    companion object {
+        private const val NO_COLOR = Color.TRANSPARENT
+        private val INVERT_MATRIX = Matrix()
+    }
+
+    private var viewTouchListener = View.OnTouchListener { _, event ->
+        notifyColorSelection(event.x.toInt(), event.y.toInt())
+        true
+    }
+
+    fun start() {
+        enableDrawingCache()
+        view.setOnTouchListener(viewTouchListener)
+    }
+
+    fun stop() {
+        disableDrawingCache()
+        view.setOnTouchListener(null)
+    }
+
+    private fun enableDrawingCache() {
+        if (view.shouldDrawingCacheBeEnabled()) {
+            view.isDrawingCacheEnabled = true
+            view.drawingCacheQuality = DRAWING_CACHE_QUALITY_LOW
+        }
+    }
+
+    private fun disableDrawingCache() {
+        if (view.shouldDrawingCacheBeEnabled()) {
+            view.isDrawingCacheEnabled = false
+        }
+    }
+
+    private fun notifyColorSelection(x: Int, y: Int) {
+        val colorAtPoint = getColorAtPoint(x, y)
+        onColorSelected.invoke(colorAtPoint)
+    }
+
+    private fun getColorAtPoint(x: Int, y: Int): Int {
+        return when (view) {
+            is ImageView -> handleIfImageView(view, x, y)
+            else -> getPixelAtPoint(view.drawingCache, x, y)
+        }
+    }
+
+    private fun handleIfImageView(view: ImageView, x: Int, y: Int): Int {
+        return when (val drawable = view.drawable) {
+            is BitmapDrawable -> {
+                view.imageMatrix.invert(INVERT_MATRIX)
+                val mappedPoints = floatArrayOf(x.toFloat(), y.toFloat())
+                INVERT_MATRIX.mapPoints(mappedPoints)
+                getPixelAtPoint(drawable.bitmap, mappedPoints[0].toInt(), mappedPoints[1].toInt())
+            }
+            else -> {
+                NO_COLOR
+            }
+        }
+    }
+
+    private fun getPixelAtPoint(bitmap: Bitmap, x: Int, y: Int): Int {
+        if (bitmap.isValidCoordinate(x, y)) {
+            return bitmap.getPixel(x, y)
+        }
+        return NO_COLOR
+    }
+
+    private fun Bitmap.isValidCoordinate(x: Int, y: Int): Boolean {
+        return x in 1 until width && y in 1 until height
+    }
+
+    private fun View.shouldDrawingCacheBeEnabled(): Boolean = (this !is ImageView) && !isDrawingCacheEnabled
+}

app/src/main/res/drawable/ic_colorise_off_vector.xml

@@ -0,0 +1,10 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24"
+    android:tint="?attr/colorControlNormal">
+  <path
+      android:fillColor="@android:color/white"
+      android:pathData="M12.126,8.125l1.937,-1.937 3.747,3.747 -1.937,1.938zM20.71,5.63l-2.34,-2.34a1,1 0,0 0,-1.41 0l-1.83,1.83 3.75,3.75L20.71,7a1,1 0,0 0,0 -1.37zM2,5l6.63,6.63L3,17.25V21h3.75l5.63,-5.62L18,21l2,-2L4,3 2,5z"/>
+</vector>

app/src/main/res/drawable/ic_colorize_vector.xml

@@ -0,0 +1,10 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24"
+    android:tint="?attr/colorControlNormal">
+  <path
+      android:fillColor="@android:color/white"
+      android:pathData="M20.71,5.63l-2.34,-2.34c-0.39,-0.39 -1.02,-0.39 -1.41,0l-3.12,3.12 -1.93,-1.91 -1.41,1.41 1.42,1.42L3,16.25V21h4.75l8.92,-8.92 1.42,1.42 1.41,-1.41 -1.92,-1.92 3.12,-3.12c0.4,-0.4 0.4,-1.03 0.01,-1.42zM6.92,19L5,17.08l8.06,-8.06 1.92,1.92L6.92,19z"/>
+</vector>

app/src/main/res/layout/activity_main.xml

@@ -23,10 +23,19 @@
         android:id="@+id/eraser"
         android:layout_width="@dimen/normal_icon_size"
         android:layout_height="@dimen/normal_icon_size"
-        android:layout_toStartOf="@+id/color_picker"
+        android:layout_toStartOf="@+id/eye_dropper"
         android:padding="@dimen/normal_margin"
         android:src="@drawable/ic_eraser_off" />
 
+    <ImageView
+        android:id="@+id/eye_dropper"
+        android:layout_width="@dimen/normal_icon_size"
+        android:layout_height="@dimen/normal_icon_size"
+        android:layout_toStartOf="@+id/color_picker"
+        android:padding="@dimen/medium_margin"
+        android:src="@drawable/ic_colorize_vector"
+        android:visibility="visible" />
+
     <ImageView
         android:id="@+id/color_picker"
         android:layout_width="@dimen/normal_icon_size"