1 /* 2 * Copyright (C) 2009 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.example.android.apis.animation; 18 19 import android.content.Context; 20 import android.content.res.TypedArray; 21 import android.util.AttributeSet; 22 import android.view.View; 23 import android.view.ViewGroup; 24 25 /** 26 * A layout that arranges its children in a grid. The size of the 27 * cells is set by the {@link #setCellSize} method and the 28 * android:cell_width and android:cell_height attributes in XML. 29 * The number of rows and columns is determined at runtime. Each 30 * cell contains exactly one view, and they flow in the natural 31 * child order (the order in which they were added, or the index 32 * in {@link #addViewAt}. Views can not span multiple cells. 33 * 34 * <p>This class was copied from the FixedGridLayout Api demo; see that demo for 35 * more information on using the layout.</p> 36 */ 37 public class FixedGridLayout extends ViewGroup { 38 int mCellWidth; 39 int mCellHeight; 40 FixedGridLayout(Context context)41 public FixedGridLayout(Context context) { 42 super(context); 43 } 44 setCellWidth(int px)45 public void setCellWidth(int px) { 46 mCellWidth = px; 47 requestLayout(); 48 } 49 setCellHeight(int px)50 public void setCellHeight(int px) { 51 mCellHeight = px; 52 requestLayout(); 53 } 54 55 @Override onMeasure(int widthMeasureSpec, int heightMeasureSpec)56 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 57 int cellWidthSpec = MeasureSpec.makeMeasureSpec(mCellWidth, 58 MeasureSpec.AT_MOST); 59 int cellHeightSpec = MeasureSpec.makeMeasureSpec(mCellHeight, 60 MeasureSpec.AT_MOST); 61 62 int count = getChildCount(); 63 for (int index=0; index<count; index++) { 64 final View child = getChildAt(index); 65 child.measure(cellWidthSpec, cellHeightSpec); 66 } 67 // Use the size our parents gave us, but default to a minimum size to avoid 68 // clipping transitioning children 69 int minCount = count > 3 ? count : 3; 70 setMeasuredDimension(resolveSize(mCellWidth * minCount, widthMeasureSpec), 71 resolveSize(mCellHeight * minCount, heightMeasureSpec)); 72 } 73 74 @Override onLayout(boolean changed, int l, int t, int r, int b)75 protected void onLayout(boolean changed, int l, int t, int r, int b) { 76 int cellWidth = mCellWidth; 77 int cellHeight = mCellHeight; 78 int columns = (r - l) / cellWidth; 79 if (columns < 0) { 80 columns = 1; 81 } 82 int x = 0; 83 int y = 0; 84 int i = 0; 85 int count = getChildCount(); 86 for (int index=0; index<count; index++) { 87 final View child = getChildAt(index); 88 89 int w = child.getMeasuredWidth(); 90 int h = child.getMeasuredHeight(); 91 92 int left = x + ((cellWidth-w)/2); 93 int top = y + ((cellHeight-h)/2); 94 95 child.layout(left, top, left+w, top+h); 96 if (i >= (columns-1)) { 97 // advance to next row 98 i = 0; 99 x = 0; 100 y += cellHeight; 101 } else { 102 i++; 103 x += cellWidth; 104 } 105 } 106 } 107 } 108 109