添加剪裁窗口颜色拾取功能

- 在工具栏添加颜色图标显示当前背景颜色
- 添加背景颜色变化监听器
- 修复画布放大时颜色拾取坐标计算
- 拾取颜色后自动退出拾取模式

gallery/src/main/java/cc/winboll/studio/gallery/CropActivity.java

@@ -98,6 +98,19 @@ public class CropActivity extends AppCompatActivity {
         });
         
         cropCanvasView = findViewById(R.id.crop_canvas_view);
+        
+        final View colorView = findViewById(R.id.color_view);
+        cropCanvasView.setOnBackgroundColorChangedListener(new CropCanvasView.OnBackgroundColorChangedListener() {
+            @Override
+            public void onBackgroundColorChanged(int color) {
+                colorView.setBackgroundColor(color);
+                cropCanvasView.setColorPickMode(false);
+                btnColorPick.setAlpha(1.0f);
+            }
+        });
+        
+        colorView.setBackgroundColor(cropCanvasView.getBackgroundColor());
+        
         loadImage();
     }
     

gallery/src/main/java/cc/winboll/studio/gallery/CropCanvasView.java

@@ -12,6 +12,15 @@ import android.view.MotionEvent;
 import android.view.View;
 
 public class CropCanvasView extends View {
+    public interface OnBackgroundColorChangedListener {
+        void onBackgroundColorChanged(int color);
+    }
+    
+    private OnBackgroundColorChangedListener backgroundColorChangedListener;
+    
+    public void setOnBackgroundColorChangedListener(OnBackgroundColorChangedListener listener) {
+        this.backgroundColorChangedListener = listener;
+    }
     private Paint imagePaint;
     private Paint borderPaint;
     private Paint cornerPaint;
@@ -39,6 +48,8 @@ public class CropCanvasView extends View {
     private RectF imageBounds = new RectF();
     private RectF canvasBounds = new RectF();
     private Bitmap originalBitmap;
+    private Bitmap canvasBitmap;
+    private float bitmapScale = 1.0f;
     private Bitmap displayBitmap;
     private RectF initialSpanRect;
     private float initialSpan;
@@ -239,6 +250,9 @@ public class CropCanvasView extends View {
     
     public void setBackgroundColor(int color) {
         this.backgroundColor = color;
+        if (backgroundColorChangedListener != null) {
+            backgroundColorChangedListener.onBackgroundColorChanged(color);
+        }
         invalidate();
     }
     
@@ -448,10 +462,16 @@ public class CropCanvasView extends View {
         
         if (colorPickMode) {
             if (event.getAction() == MotionEvent.ACTION_DOWN) {
-                pickX = x;
-                pickY = y;
-                int color = getColorAt(x, y);
-                setBackgroundColor(color);
+                if (originalBitmap != null && !originalBitmap.isRecycled()) {
+                    float imgX = screenToImageX(x);
+                    float imgY = screenToImageY(y);
+                    int bmpX = (int) ((imgX - imageBounds.left) / displayScale * displayBitmapScale);
+                    int bmpY = (int) ((imgY - imageBounds.top) / displayScale * displayBitmapScale);
+                    bmpX = Math.max(0, Math.min(bmpX, originalBitmap.getWidth() - 1));
+                    bmpY = Math.max(0, Math.min(bmpY, originalBitmap.getHeight() - 1));
+                    int color = originalBitmap.getPixel(bmpX, bmpY);
+                    setBackgroundColor(color);
+                }
                 return true;
             }
             return true;