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 private static final String TAG = "EdgeView"; 25 26 public static final int INVALID_DIRECTION = -1; 27 public static final int TOP = 0; 28 public static final int LEFT = 1; 29 public static final int BOTTOM = 2; 30 public static final int RIGHT = 3; 31 32 // Each edge effect has a transform matrix, and each matrix has 16 elements. 33 // We put all the elements in one array. These constants specify the 34 // starting index of each matrix. 35 private static final int TOP_M = TOP * 16; 36 private static final int LEFT_M = LEFT * 16; 37 private static final int BOTTOM_M = BOTTOM * 16; 38 private static final int RIGHT_M = RIGHT * 16; 39 40 private EdgeEffect[] mEffect = new EdgeEffect[4]; 41 private float[] mMatrix = new float[4 * 16]; 42 EdgeView(Context context)43 public EdgeView(Context context) { 44 for (int i = 0; i < 4; i++) { 45 mEffect[i] = new EdgeEffect(context); 46 } 47 } 48 49 @Override onLayout( boolean changeSize, int left, int top, int right, int bottom)50 protected void onLayout( 51 boolean changeSize, int left, int top, int right, int bottom) { 52 if (!changeSize) return; 53 54 int w = right - left; 55 int h = bottom - top; 56 for (int i = 0; i < 4; i++) { 57 if ((i & 1) == 0) { // top or bottom 58 mEffect[i].setSize(w, h); 59 } else { // left or right 60 mEffect[i].setSize(h, w); 61 } 62 } 63 64 // Set up transforms for the four edges. Without transforms an 65 // EdgeEffect draws the TOP edge from (0, 0) to (w, Y * h) where Y 66 // is some factor < 1. For other edges we need to move, rotate, and 67 // flip the effects into proper places. 68 Matrix.setIdentityM(mMatrix, TOP_M); 69 Matrix.setIdentityM(mMatrix, LEFT_M); 70 Matrix.setIdentityM(mMatrix, BOTTOM_M); 71 Matrix.setIdentityM(mMatrix, RIGHT_M); 72 73 Matrix.rotateM(mMatrix, LEFT_M, 90, 0, 0, 1); 74 Matrix.scaleM(mMatrix, LEFT_M, 1, -1, 1); 75 76 Matrix.translateM(mMatrix, BOTTOM_M, 0, h, 0); 77 Matrix.scaleM(mMatrix, BOTTOM_M, 1, -1, 1); 78 79 Matrix.translateM(mMatrix, RIGHT_M, w, 0, 0); 80 Matrix.rotateM(mMatrix, RIGHT_M, 90, 0, 0, 1); 81 } 82 83 @Override render(GLCanvas canvas)84 protected void render(GLCanvas canvas) { 85 super.render(canvas); 86 boolean more = false; 87 for (int i = 0; i < 4; i++) { 88 canvas.save(GLCanvas.SAVE_FLAG_MATRIX); 89 canvas.multiplyMatrix(mMatrix, i * 16); 90 more |= mEffect[i].draw(canvas); 91 canvas.restore(); 92 } 93 if (more) { 94 invalidate(); 95 } 96 } 97 98 // Called when the content is pulled away from the edge. 99 // offset is in pixels. direction is one of {TOP, LEFT, BOTTOM, RIGHT}. onPull(int offset, int direction)100 public void onPull(int offset, int direction) { 101 int fullLength = ((direction & 1) == 0) ? getWidth() : getHeight(); 102 mEffect[direction].onPull((float)offset / fullLength); 103 if (!mEffect[direction].isFinished()) { 104 invalidate(); 105 } 106 } 107 108 // Call when the object is released after being pulled. onRelease()109 public void onRelease() { 110 boolean more = false; 111 for (int i = 0; i < 4; i++) { 112 mEffect[i].onRelease(); 113 more |= !mEffect[i].isFinished(); 114 } 115 if (more) { 116 invalidate(); 117 } 118 } 119 120 // Call when the effect absorbs an impact at the given velocity. 121 // Used when a fling reaches the scroll boundary. velocity is in pixels 122 // per second. direction is one of {TOP, LEFT, BOTTOM, RIGHT}. onAbsorb(int velocity, int direction)123 public void onAbsorb(int velocity, int direction) { 124 mEffect[direction].onAbsorb(velocity); 125 if (!mEffect[direction].isFinished()) { 126 invalidate(); 127 } 128 } 129 } 130