/* * Copyright (C) 2010 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.graphics; import com.android.ide.common.rendering.api.LayoutLog; import com.android.layoutlib.bridge.Bridge; import com.android.layoutlib.bridge.impl.DelegateManager; import com.android.tools.layoutlib.annotations.LayoutlibDelegate; import android.graphics.Shader.TileMode; import java.awt.image.ColorModel; /** * Delegate implementing the native methods of android.graphics.LinearGradient * * Through the layoutlib_create tool, the original native methods of LinearGradient have been * replaced by calls to methods of the same name in this delegate class. * * This class behaves like the original native implementation, but in Java, keeping previously * native data into its own objects and mapping them to int that are sent back and forth between * it and the original LinearGradient class. * * Because this extends {@link Shader_Delegate}, there's no need to use a {@link DelegateManager}, * as all the Shader classes will be added to the manager owned by {@link Shader_Delegate}. * * @see Shader_Delegate * */ public final class LinearGradient_Delegate extends Gradient_Delegate { // ---- delegate data ---- private java.awt.Paint mJavaPaint; // ---- Public Helper methods ---- @Override public java.awt.Paint getJavaPaint() { return mJavaPaint; } // ---- native methods ---- @LayoutlibDelegate /*package*/ static long nativeCreate1(LinearGradient thisGradient, long matrix, float x0, float y0, float x1, float y1, int colors[], float positions[], int tileMode) { LinearGradient_Delegate newDelegate = new LinearGradient_Delegate(matrix, x0, y0, x1, y1, colors, positions, Shader_Delegate.getTileMode(tileMode)); return sManager.addNewDelegate(newDelegate); } @LayoutlibDelegate /*package*/ static long nativeCreate2(LinearGradient thisGradient, long matrix, float x0, float y0, float x1, float y1, int color0, int color1, int tileMode) { return nativeCreate1(thisGradient, matrix, x0, y0, x1, y1, new int[] { color0, color1}, null /*positions*/, tileMode); } // ---- Private delegate/helper methods ---- /** * Create a shader that draws a linear gradient along a line. * * @param nativeMatrix reference to the shader's native transformation matrix * @param x0 The x-coordinate for the start of the gradient line * @param y0 The y-coordinate for the start of the gradient line * @param x1 The x-coordinate for the end of the gradient line * @param y1 The y-coordinate for the end of the gradient line * @param colors The colors to be distributed along the gradient line * @param positions May be null. The relative positions [0..1] of each * corresponding color in the colors array. If this is null, the * the colors are distributed evenly along the gradient line. * @param tile The Shader tiling mode */ private LinearGradient_Delegate(long nativeMatrix, float x0, float y0, float x1, float y1, int colors[], float positions[], TileMode tile) { super(nativeMatrix, colors, positions); mJavaPaint = new LinearGradientPaint(x0, y0, x1, y1, mColors, mPositions, tile); } // ---- Custom Java Paint ---- /** * Linear Gradient (Java) Paint able to handle more than 2 points, as * {@link java.awt.GradientPaint} only supports 2 points and does not support Android's tile * modes. */ private class LinearGradientPaint extends GradientPaint { private final float mX0; private final float mY0; private final float mDx; private final float mDy; private final float mDSize2; public LinearGradientPaint(float x0, float y0, float x1, float y1, int colors[], float positions[], TileMode tile) { super(colors, positions, tile); mX0 = x0; mY0 = y0; mDx = x1 - x0; mDy = y1 - y0; mDSize2 = mDx * mDx + mDy * mDy; } @Override public java.awt.PaintContext createContext( java.awt.image.ColorModel colorModel, java.awt.Rectangle deviceBounds, java.awt.geom.Rectangle2D userBounds, java.awt.geom.AffineTransform xform, java.awt.RenderingHints hints) { precomputeGradientColors(); java.awt.geom.AffineTransform canvasMatrix; try { canvasMatrix = xform.createInverse(); } catch (java.awt.geom.NoninvertibleTransformException e) { Bridge.getLog().fidelityWarning(LayoutLog.TAG_MATRIX_INVERSE, "Unable to inverse matrix in LinearGradient", e, null /*data*/); canvasMatrix = new java.awt.geom.AffineTransform(); } java.awt.geom.AffineTransform localMatrix = getLocalMatrix(); try { localMatrix = localMatrix.createInverse(); } catch (java.awt.geom.NoninvertibleTransformException e) { Bridge.getLog().fidelityWarning(LayoutLog.TAG_MATRIX_INVERSE, "Unable to inverse matrix in LinearGradient", e, null /*data*/); localMatrix = new java.awt.geom.AffineTransform(); } return new LinearGradientPaintContext(canvasMatrix, localMatrix, colorModel); } private class LinearGradientPaintContext implements java.awt.PaintContext { private final java.awt.geom.AffineTransform mCanvasMatrix; private final java.awt.geom.AffineTransform mLocalMatrix; private final java.awt.image.ColorModel mColorModel; private LinearGradientPaintContext( java.awt.geom.AffineTransform canvasMatrix, java.awt.geom.AffineTransform localMatrix, java.awt.image.ColorModel colorModel) { mCanvasMatrix = canvasMatrix; mLocalMatrix = localMatrix; mColorModel = colorModel.hasAlpha() ? colorModel : ColorModel.getRGBdefault(); } @Override public void dispose() { } @Override public java.awt.image.ColorModel getColorModel() { return mColorModel; } @Override public java.awt.image.Raster getRaster(int x, int y, int w, int h) { java.awt.image.BufferedImage image = new java.awt.image.BufferedImage( mColorModel, mColorModel.createCompatibleWritableRaster(w, h), mColorModel.isAlphaPremultiplied(), null); int[] data = new int[w*h]; int index = 0; float[] pt1 = new float[2]; float[] pt2 = new float[2]; for (int iy = 0 ; iy < h ; iy++) { for (int ix = 0 ; ix < w ; ix++) { // handle the canvas transform pt1[0] = x + ix; pt1[1] = y + iy; mCanvasMatrix.transform(pt1, 0, pt2, 0, 1); // handle the local matrix. pt1[0] = pt2[0]; pt1[1] = pt2[1]; mLocalMatrix.transform(pt1, 0, pt2, 0, 1); data[index++] = getColor(pt2[0], pt2[1]); } } image.setRGB(0 /*startX*/, 0 /*startY*/, w, h, data, 0 /*offset*/, w /*scansize*/); return image.getRaster(); } } /** * Returns a color for an arbitrary point. */ private int getColor(float x, float y) { float pos; if (mDx == 0) { pos = (y - mY0) / mDy; } else if (mDy == 0) { pos = (x - mX0) / mDx; } else { // find the x position on the gradient vector. float _x = (mDx*mDy*(y-mY0) + mDy*mDy*mX0 + mDx*mDx*x) / mDSize2; // from it get the position relative to the vector pos = (_x - mX0) / mDx; } return getGradientColor(pos); } } }