1 files changed, 129 insertions, 0 deletions
diff --git a/src/afzkl/development/mColorPicker/drawables/AlphaPatternDrawable.java b/src/afzkl/development/mColorPicker/drawables/AlphaPatternDrawable.java
new file mode 100644
index 0000000..e878756
--- /dev/null
+++ b/src/afzkl/development/mColorPicker/drawables/AlphaPatternDrawable.java
@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) 2010 Daniel Nilsson
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package afzkl.development.mColorPicker.drawables;
+
+import android.graphics.Bitmap;
+import android.graphics.Bitmap.Config;
+import android.graphics.Canvas;
+import android.graphics.ColorFilter;
+import android.graphics.Paint;
+import android.graphics.Rect;
+import android.graphics.drawable.Drawable;
+
+/**
+ * This drawable that draws a simple white and gray chessboard pattern.
+ * It's pattern you will often see as a background behind a
+ * partly transparent image in many applications.
+ * @author Daniel Nilsson
+ */
+@SuppressWarnings("all")
+public class AlphaPatternDrawable extends Drawable {
+
+    private int mRectangleSize = 10;
+
+    private final Paint mPaint = new Paint();
+    private final Paint mPaintWhite = new Paint();
+    private final Paint mPaintGray = new Paint();
+
+    private int numRectanglesHorizontal;
+    private int numRectanglesVertical;
+
+    /**
+     * Bitmap in which the pattern will be cahched.
+     */
+    private Bitmap        mBitmap;
+
+    public AlphaPatternDrawable(int rectangleSize) {
+        mRectangleSize = rectangleSize;
+        mPaintWhite.setColor(0xffffffff);
+        mPaintGray.setColor(0xffcbcbcb);
+    }
+
+    @Override
+    public void draw(Canvas canvas) {
+        canvas.drawBitmap(mBitmap, null, getBounds(), mPaint);
+    }
+
+    @Override
+    public int getOpacity() {
+        return 0;
+    }
+
+    @Override
+    public void setAlpha(int alpha) {
+        throw new UnsupportedOperationException("Alpha is not supported by this drawwable.");
+    }
+
+    @Override
+    public void setColorFilter(ColorFilter cf) {
+        throw new UnsupportedOperationException("ColorFilter is not supported by this drawwable.");
+    }
+
+    @Override
+    protected void onBoundsChange(Rect bounds) {
+        super.onBoundsChange(bounds);
+
+        int height = bounds.height();
+        int width = bounds.width();
+
+        numRectanglesHorizontal = (int) Math.ceil((width / mRectangleSize));
+        numRectanglesVertical = (int) Math.ceil(height / mRectangleSize);
+
+        generatePatternBitmap();
+
+    }
+
+    /**
+     * This will generate a bitmap with the pattern
+     * as big as the rectangle we were allow to draw on.
+     * We do this to chache the bitmap so we don't need to
+     * recreate it each time draw() is called since it
+     * takes a few milliseconds.
+     */
+    private void generatePatternBitmap() {
+
+        if (getBounds().width() <= 0 || getBounds().height() <= 0) {
+            return;
+        }
+
+        mBitmap = Bitmap.createBitmap(getBounds().width(), getBounds().height(), Config.ARGB_8888);
+        Canvas canvas = new Canvas(mBitmap);
+
+        Rect r = new Rect();
+        boolean verticalStartWhite = true;
+        for (int i = 0; i <= numRectanglesVertical; i++) {
+
+            boolean isWhite = verticalStartWhite;
+            for (int j = 0; j <= numRectanglesHorizontal; j++) {
+
+                r.top = i * mRectangleSize;
+                r.left = j * mRectangleSize;
+                r.bottom = r.top + mRectangleSize;
+                r.right = r.left + mRectangleSize;
+
+                canvas.drawRect(r, isWhite ? mPaintWhite : mPaintGray);
+
+                isWhite = !isWhite;
+            }
+
+            verticalStartWhite = !verticalStartWhite;
+
+        }
+
+    }
+
+}