am 3cf0640d: Merge "Add primitive shadows support to LayoutLib" into lmp-dev automerge: 97c04ac

* commit '3cf0640d944a0718b9e29a2134a577e72a9432b4':
  Add primitive shadows support to LayoutLib

1 files changed, 415 insertions, 0 deletions

diff --git a/tools/layoutlib/bridge/src/android/view/ShadowPainter.java b/tools/layoutlib/bridge/src/android/view/ShadowPainter.java
new file mode 100644
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+++ b/tools/layoutlib/bridge/src/android/view/ShadowPainter.java
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+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * 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 android.view;
+
+import com.android.annotations.NonNull;
+
+import java.awt.Graphics2D;
+import java.awt.Image;
+import java.awt.image.BufferedImage;
+import java.awt.image.DataBufferInt;
+import java.io.IOException;
+import java.io.InputStream;
+
+import javax.imageio.ImageIO;
+
+public class ShadowPainter {
+
+    /**
+     * Adds a drop shadow to a semi-transparent image (of an arbitrary shape) and returns it as a
+     * new image. This method attempts to mimic the same visual characteristics as the rectangular
+     * shadow painting methods in this class, {@link #createRectangularDropShadow(java.awt.image.BufferedImage)}
+     * and {@link #createSmallRectangularDropShadow(java.awt.image.BufferedImage)}.
+     *
+     * @param source the source image
+     * @param shadowSize the size of the shadow, normally {@link #SHADOW_SIZE or {@link
+     * #SMALL_SHADOW_SIZE}}
+     *
+     * @return a new image with the shadow painted in
+     */
+    @NonNull
+    public static BufferedImage createDropShadow(BufferedImage source, int shadowSize) {
+        shadowSize /= 2; // make shadow size have the same meaning as in the other shadow paint methods in this class
+
+        return createDropShadow(source, shadowSize, 0.7f, 0);
+    }
+
+    /**
+     * Creates a drop shadow of a given image and returns a new image which shows the input image on
+     * top of its drop shadow.
+     * <p/>
+     * <b>NOTE: If the shape is rectangular and opaque, consider using {@link
+     * #drawRectangleShadow(Graphics2D, int, int, int, int)} instead.</b>
+     *
+     * @param source the source image to be shadowed
+     * @param shadowSize the size of the shadow in pixels
+     * @param shadowOpacity the opacity of the shadow, with 0=transparent and 1=opaque
+     * @param shadowRgb the RGB int to use for the shadow color
+     *
+     * @return a new image with the source image on top of its shadow
+     */
+    @SuppressWarnings({"SuspiciousNameCombination", "UnnecessaryLocalVariable"})  // Imported code
+    public static BufferedImage createDropShadow(BufferedImage source, int shadowSize,
+            float shadowOpacity, int shadowRgb) {
+
+        // This code is based on
+        //      http://www.jroller.com/gfx/entry/non_rectangular_shadow
+
+        BufferedImage image;
+        int width = source.getWidth();
+        int height = source.getHeight();
+        image = new BufferedImage(width + SHADOW_SIZE, height + SHADOW_SIZE,
+                BufferedImage.TYPE_INT_ARGB);
+
+        Graphics2D g2 = image.createGraphics();
+        g2.drawImage(image, shadowSize, shadowSize, null);
+
+        int dstWidth = image.getWidth();
+        int dstHeight = image.getHeight();
+
+        int left = (shadowSize - 1) >> 1;
+        int right = shadowSize - left;
+        int xStart = left;
+        int xStop = dstWidth - right;
+        int yStart = left;
+        int yStop = dstHeight - right;
+
+        shadowRgb &= 0x00FFFFFF;
+
+        int[] aHistory = new int[shadowSize];
+        int historyIdx;
+
+        int aSum;
+
+        int[] dataBuffer = ((DataBufferInt) image.getRaster().getDataBuffer()).getData();
+        int lastPixelOffset = right * dstWidth;
+        float sumDivider = shadowOpacity / shadowSize;
+
+        // horizontal pass
+        for (int y = 0, bufferOffset = 0; y < dstHeight; y++, bufferOffset = y * dstWidth) {
+            aSum = 0;
+            historyIdx = 0;
+            for (int x = 0; x < shadowSize; x++, bufferOffset++) {
+                int a = dataBuffer[bufferOffset] >>> 24;
+                aHistory[x] = a;
+                aSum += a;
+            }
+
+            bufferOffset -= right;
+
+            for (int x = xStart; x < xStop; x++, bufferOffset++) {
+                int a = (int) (aSum * sumDivider);
+                dataBuffer[bufferOffset] = a << 24 | shadowRgb;
+
+                // subtract the oldest pixel from the sum
+                aSum -= aHistory[historyIdx];
+
+                // get the latest pixel
+                a = dataBuffer[bufferOffset + right] >>> 24;
+                aHistory[historyIdx] = a;
+                aSum += a;
+
+                if (++historyIdx >= shadowSize) {
+                    historyIdx -= shadowSize;
+                }
+            }
+        }
+        // vertical pass
+        for (int x = 0, bufferOffset = 0; x < dstWidth; x++, bufferOffset = x) {
+            aSum = 0;
+            historyIdx = 0;
+            for (int y = 0; y < shadowSize; y++, bufferOffset += dstWidth) {
+                int a = dataBuffer[bufferOffset] >>> 24;
+                aHistory[y] = a;
+                aSum += a;
+            }
+
+            bufferOffset -= lastPixelOffset;
+
+            for (int y = yStart; y < yStop; y++, bufferOffset += dstWidth) {
+                int a = (int) (aSum * sumDivider);
+                dataBuffer[bufferOffset] = a << 24 | shadowRgb;
+
+                // subtract the oldest pixel from the sum
+                aSum -= aHistory[historyIdx];
+
+                // get the latest pixel
+                a = dataBuffer[bufferOffset + lastPixelOffset] >>> 24;
+                aHistory[historyIdx] = a;
+                aSum += a;
+
+                if (++historyIdx >= shadowSize) {
+                    historyIdx -= shadowSize;
+                }
+            }
+        }
+
+        g2.drawImage(source, null, 0, 0);
+        g2.dispose();
+
+        return image;
+    }
+
+    /**
+     * Draws a rectangular drop shadow (of size {@link #SHADOW_SIZE} by {@link #SHADOW_SIZE} around
+     * the given source and returns a new image with both combined
+     *
+     * @param source the source image
+     *
+     * @return the source image with a drop shadow on the bottom and right
+     */
+    @SuppressWarnings("UnusedDeclaration")
+    public static BufferedImage createRectangularDropShadow(BufferedImage source) {
+        int type = source.getType();
+        if (type == BufferedImage.TYPE_CUSTOM) {
+            type = BufferedImage.TYPE_INT_ARGB;
+        }
+
+        int width = source.getWidth();
+        int height = source.getHeight();
+        BufferedImage image;
+        image = new BufferedImage(width + SHADOW_SIZE, height + SHADOW_SIZE, type);
+        Graphics2D g = image.createGraphics();
+        g.drawImage(source, 0, 0, null);
+        drawRectangleShadow(image, 0, 0, width, height);
+        g.dispose();
+
+        return image;
+    }
+
+    /**
+     * Draws a small rectangular drop shadow (of size {@link #SMALL_SHADOW_SIZE} by {@link
+     * #SMALL_SHADOW_SIZE} around the given source and returns a new image with both combined
+     *
+     * @param source the source image
+     *
+     * @return the source image with a drop shadow on the bottom and right
+     */
+    @SuppressWarnings("UnusedDeclaration")
+    public static BufferedImage createSmallRectangularDropShadow(BufferedImage source) {
+        int type = source.getType();
+        if (type == BufferedImage.TYPE_CUSTOM) {
+            type = BufferedImage.TYPE_INT_ARGB;
+        }
+
+        int width = source.getWidth();
+        int height = source.getHeight();
+
+        BufferedImage image;
+        image = new BufferedImage(width + SMALL_SHADOW_SIZE, height + SMALL_SHADOW_SIZE, type);
+
+        Graphics2D g = image.createGraphics();
+        g.drawImage(source, 0, 0, null);
+        drawSmallRectangleShadow(image, 0, 0, width, height);
+        g.dispose();
+
+        return image;
+    }
+
+    /**
+     * Draws a drop shadow for the given rectangle into the given context. It will not draw anything
+     * if the rectangle is smaller than a minimum determined by the assets used to draw the shadow
+     * graphics. The size of the shadow is {@link #SHADOW_SIZE}.
+     *
+     * @param image the image to draw the shadow into
+     * @param x the left coordinate of the left hand side of the rectangle
+     * @param y the top coordinate of the top of the rectangle
+     * @param width the width of the rectangle
+     * @param height the height of the rectangle
+     */
+    public static void drawRectangleShadow(BufferedImage image,
+            int x, int y, int width, int height) {
+        Graphics2D gc = image.createGraphics();
+        try {
+            drawRectangleShadow(gc, x, y, width, height);
+        } finally {
+            gc.dispose();
+        }
+    }
+
+    /**
+     * Draws a small drop shadow for the given rectangle into the given context. It will not draw
+     * anything if the rectangle is smaller than a minimum determined by the assets used to draw the
+     * shadow graphics. The size of the shadow is {@link #SMALL_SHADOW_SIZE}.
+     *
+     * @param image the image to draw the shadow into
+     * @param x the left coordinate of the left hand side of the rectangle
+     * @param y the top coordinate of the top of the rectangle
+     * @param width the width of the rectangle
+     * @param height the height of the rectangle
+     */
+    public static void drawSmallRectangleShadow(BufferedImage image,
+            int x, int y, int width, int height) {
+        Graphics2D gc = image.createGraphics();
+        try {
+            drawSmallRectangleShadow(gc, x, y, width, height);
+        } finally {
+            gc.dispose();
+        }
+    }
+
+    /**
+     * The width and height of the drop shadow painted by
+     * {@link #drawRectangleShadow(Graphics2D, int, int, int, int)}
+     */
+    public static final int SHADOW_SIZE = 20; // DO NOT EDIT. This corresponds to bitmap graphics
+
+    /**
+     * The width and height of the drop shadow painted by
+     * {@link #drawSmallRectangleShadow(Graphics2D, int, int, int, int)}
+     */
+    public static final int SMALL_SHADOW_SIZE = 10; // DO NOT EDIT. Corresponds to bitmap graphics
+
+    /**
+     * Draws a drop shadow for the given rectangle into the given context. It will not draw anything
+     * if the rectangle is smaller than a minimum determined by the assets used to draw the shadow
+     * graphics.
+     *
+     * @param gc the graphics context to draw into
+     * @param x the left coordinate of the left hand side of the rectangle
+     * @param y the top coordinate of the top of the rectangle
+     * @param width the width of the rectangle
+     * @param height the height of the rectangle
+     */
+    public static void drawRectangleShadow(Graphics2D gc, int x, int y, int width, int height) {
+        assert ShadowBottomLeft != null;
+        assert ShadowBottomRight.getWidth(null) == SHADOW_SIZE;
+        assert ShadowBottomRight.getHeight(null) == SHADOW_SIZE;
+
+        int blWidth = ShadowBottomLeft.getWidth(null);
+        int trHeight = ShadowTopRight.getHeight(null);
+        if (width < blWidth) {
+            return;
+        }
+        if (height < trHeight) {
+            return;
+        }
+
+        gc.drawImage(ShadowBottomLeft, x - ShadowBottomLeft.getWidth(null), y + height, null);
+        gc.drawImage(ShadowBottomRight, x + width, y + height, null);
+        gc.drawImage(ShadowTopRight, x + width, y, null);
+        gc.drawImage(ShadowTopLeft, x - ShadowTopLeft.getWidth(null), y, null);
+        gc.drawImage(ShadowBottom,
+                x, y + height, x + width, y + height + ShadowBottom.getHeight(null),
+                0, 0, ShadowBottom.getWidth(null), ShadowBottom.getHeight(null), null);
+        gc.drawImage(ShadowRight,
+                x + width, y + ShadowTopRight.getHeight(null), x + width + ShadowRight.getWidth(null), y + height,
+                0, 0, ShadowRight.getWidth(null), ShadowRight.getHeight(null), null);
+        gc.drawImage(ShadowLeft,
+                x - ShadowLeft.getWidth(null), y + ShadowTopLeft.getHeight(null), x, y + height,
+                0, 0, ShadowLeft.getWidth(null), ShadowLeft.getHeight(null), null);
+    }
+
+    /**
+     * Draws a small drop shadow for the given rectangle into the given context. It will not draw
+     * anything if the rectangle is smaller than a minimum determined by the assets used to draw the
+     * shadow graphics.
+     * <p/>
+     *
+     * @param gc the graphics context to draw into
+     * @param x the left coordinate of the left hand side of the rectangle
+     * @param y the top coordinate of the top of the rectangle
+     * @param width the width of the rectangle
+     * @param height the height of the rectangle
+     */
+    public static void drawSmallRectangleShadow(Graphics2D gc, int x, int y, int width,
+            int height) {
+        assert Shadow2BottomLeft != null;
+        assert Shadow2TopRight != null;
+        assert Shadow2BottomRight.getWidth(null) == SMALL_SHADOW_SIZE;
+        assert Shadow2BottomRight.getHeight(null) == SMALL_SHADOW_SIZE;
+
+        int blWidth = Shadow2BottomLeft.getWidth(null);
+        int trHeight = Shadow2TopRight.getHeight(null);
+        if (width < blWidth) {
+            return;
+        }
+        if (height < trHeight) {
+            return;
+        }
+
+        gc.drawImage(Shadow2BottomLeft, x - Shadow2BottomLeft.getWidth(null), y + height, null);
+        gc.drawImage(Shadow2BottomRight, x + width, y + height, null);
+        gc.drawImage(Shadow2TopRight, x + width, y, null);
+        gc.drawImage(Shadow2TopLeft, x - Shadow2TopLeft.getWidth(null), y, null);
+        gc.drawImage(Shadow2Bottom,
+                x, y + height, x + width, y + height + Shadow2Bottom.getHeight(null),
+                0, 0, Shadow2Bottom.getWidth(null), Shadow2Bottom.getHeight(null), null);
+        gc.drawImage(Shadow2Right,
+                x + width, y + Shadow2TopRight.getHeight(null), x + width + Shadow2Right.getWidth(null), y + height,
+                0, 0, Shadow2Right.getWidth(null), Shadow2Right.getHeight(null), null);
+        gc.drawImage(Shadow2Left,
+                x - Shadow2Left.getWidth(null), y + Shadow2TopLeft.getHeight(null), x, y + height,
+                0, 0, Shadow2Left.getWidth(null), Shadow2Left.getHeight(null), null);
+    }
+
+    private static Image loadIcon(String name) {
+        InputStream inputStream = ShadowPainter.class.getResourceAsStream(name);
+        if (inputStream == null) {
+            throw new RuntimeException("Unable to load image for shadow: " + name);
+        }
+        try {
+            return ImageIO.read(inputStream);
+        } catch (IOException e) {
+            throw new RuntimeException("Unable to load image for shadow:" + name, e);
+        } finally {
+            try {
+                inputStream.close();
+            } catch (IOException e) {
+                // ignore.
+            }
+        }
+    }
+
+    // Shadow graphics. This was generated by creating a drop shadow in
+    // Gimp, using the parameters x offset=10, y offset=10, blur radius=10,
+    // (for the small drop shadows x offset=10, y offset=10, blur radius=10)
+    // color=black, and opacity=51. These values attempt to make a shadow
+    // that is legible both for dark and light themes, on top of the
+    // canvas background (rgb(150,150,150). Darker shadows would tend to
+    // blend into the foreground for a dark holo screen, and lighter shadows
+    // would be hard to spot on the canvas background. If you make adjustments,
+    // make sure to check the shadow with both dark and light themes.
+    //
+    // After making the graphics, I cut out the top right, bottom left
+    // and bottom right corners as 20x20 images, and these are reproduced by
+    // painting them in the corresponding places in the target graphics context.
+    // I then grabbed a single horizontal gradient line from the middle of the
+    // right edge,and a single vertical gradient line from the bottom. These
+    // are then painted scaled/stretched in the target to fill the gaps between
+    // the three corner images.
+    //
+    // Filenames: bl=bottom left, b=bottom, br=bottom right, r=right, tr=top right
+
+    // Normal Drop Shadow
+    private static final Image ShadowBottom = loadIcon("/icons/shadow-b.png");
+    private static final Image ShadowBottomLeft = loadIcon("/icons/shadow-bl.png");
+    private static final Image ShadowBottomRight = loadIcon("/icons/shadow-br.png");
+    private static final Image ShadowRight = loadIcon("/icons/shadow-r.png");
+    private static final Image ShadowTopRight = loadIcon("/icons/shadow-tr.png");
+    private static final Image ShadowTopLeft = loadIcon("/icons/shadow-tl.png");
+    private static final Image ShadowLeft = loadIcon("/icons/shadow-l.png");
+
+    // Small Drop Shadow
+    private static final Image Shadow2Bottom = loadIcon("/icons/shadow2-b.png");
+    private static final Image Shadow2BottomLeft = loadIcon("/icons/shadow2-bl.png");
+    private static final Image Shadow2BottomRight = loadIcon("/icons/shadow2-br.png");
+    private static final Image Shadow2Right = loadIcon("/icons/shadow2-r.png");
+    private static final Image Shadow2TopRight = loadIcon("/icons/shadow2-tr.png");
+    private static final Image Shadow2TopLeft = loadIcon("/icons/shadow2-tl.png");
+    private static final Image Shadow2Left = loadIcon("/icons/shadow2-l.png");
+}