1 /* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.gallery3d.ui; 18 19 import android.content.Context; 20 import android.opengl.Matrix; 21 22 // EdgeView draws EdgeEffect (blue glow) at four sides of the view. 23 public class EdgeView extends GLView { 24 @SuppressWarnings("unused") 25 private static final String TAG = "EdgeView"; 26 27 public static final int INVALID_DIRECTION = -1; 28 public static final int TOP = 0; 29 public static final int LEFT = 1; 30 public static final int BOTTOM = 2; 31 public static final int RIGHT = 3; 32 33 // Each edge effect has a transform matrix, and each matrix has 16 elements. 34 // We put all the elements in one array. These constants specify the 35 // starting index of each matrix. 36 private static final int TOP_M = TOP * 16; 37 private static final int LEFT_M = LEFT * 16; 38 private static final int BOTTOM_M = BOTTOM * 16; 39 private static final int RIGHT_M = RIGHT * 16; 40 41 private EdgeEffect[] mEffect = new EdgeEffect[4]; 42 private float[] mMatrix = new float[4 * 16]; 43 EdgeView(Context context)44 public EdgeView(Context context) { 45 for (int i = 0; i < 4; i++) { 46 mEffect[i] = new EdgeEffect(context); 47 } 48 } 49 50 @Override onLayout( boolean changeSize, int left, int top, int right, int bottom)51 protected void onLayout( 52 boolean changeSize, int left, int top, int right, int bottom) { 53 if (!changeSize) return; 54 55 int w = right - left; 56 int h = bottom - top; 57 for (int i = 0; i < 4; i++) { 58 if ((i & 1) == 0) { // top or bottom 59 mEffect[i].setSize(w, h); 60 } else { // left or right 61 mEffect[i].setSize(h, w); 62 } 63 } 64 65 // Set up transforms for the four edges. Without transforms an 66 // EdgeEffect draws the TOP edge from (0, 0) to (w, Y * h) where Y 67 // is some factor < 1. For other edges we need to move, rotate, and 68 // flip the effects into proper places. 69 Matrix.setIdentityM(mMatrix, TOP_M); 70 Matrix.setIdentityM(mMatrix, LEFT_M); 71 Matrix.setIdentityM(mMatrix, BOTTOM_M); 72 Matrix.setIdentityM(mMatrix, RIGHT_M); 73 74 Matrix.rotateM(mMatrix, LEFT_M, 90, 0, 0, 1); 75 Matrix.scaleM(mMatrix, LEFT_M, 1, -1, 1); 76 77 Matrix.translateM(mMatrix, BOTTOM_M, 0, h, 0); 78 Matrix.scaleM(mMatrix, BOTTOM_M, 1, -1, 1); 79 80 Matrix.translateM(mMatrix, RIGHT_M, w, 0, 0); 81 Matrix.rotateM(mMatrix, RIGHT_M, 90, 0, 0, 1); 82 } 83 84 @Override render(GLCanvas canvas)85 protected void render(GLCanvas canvas) { 86 super.render(canvas); 87 boolean more = false; 88 for (int i = 0; i < 4; i++) { 89 canvas.save(GLCanvas.SAVE_FLAG_MATRIX); 90 canvas.multiplyMatrix(mMatrix, i * 16); 91 more |= mEffect[i].draw(canvas); 92 canvas.restore(); 93 } 94 if (more) { 95 invalidate(); 96 } 97 } 98 99 // Called when the content is pulled away from the edge. 100 // offset is in pixels. direction is one of {TOP, LEFT, BOTTOM, RIGHT}. onPull(int offset, int direction)101 public void onPull(int offset, int direction) { 102 int fullLength = ((direction & 1) == 0) ? getWidth() : getHeight(); 103 mEffect[direction].onPull((float)offset / fullLength); 104 if (!mEffect[direction].isFinished()) { 105 invalidate(); 106 } 107 } 108 109 // Call when the object is released after being pulled. onRelease()110 public void onRelease() { 111 boolean more = false; 112 for (int i = 0; i < 4; i++) { 113 mEffect[i].onRelease(); 114 more |= !mEffect[i].isFinished(); 115 } 116 if (more) { 117 invalidate(); 118 } 119 } 120 121 // Call when the effect absorbs an impact at the given velocity. 122 // Used when a fling reaches the scroll boundary. velocity is in pixels 123 // per second. direction is one of {TOP, LEFT, BOTTOM, RIGHT}. onAbsorb(int velocity, int direction)124 public void onAbsorb(int velocity, int direction) { 125 mEffect[direction].onAbsorb(velocity); 126 if (!mEffect[direction].isFinished()) { 127 invalidate(); 128 } 129 } 130 } 131