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 android.support.v7.widget; 18 19 import android.content.Context; 20 import android.graphics.Canvas; 21 import android.util.AttributeSet; 22 import android.view.View; 23 import android.view.ViewGroup; 24 25 /** 26 * Space is a lightweight View subclass that may be used to create gaps between components 27 * in general purpose layouts. 28 */ 29 public final class Space extends View { 30 /** 31 * {@inheritDoc} 32 */ Space(Context context, AttributeSet attrs, int defStyle)33 public Space(Context context, AttributeSet attrs, int defStyle) { 34 super(context, attrs, defStyle); 35 if (getVisibility() == VISIBLE) { 36 setVisibility(INVISIBLE); 37 } 38 } 39 40 /** 41 * {@inheritDoc} 42 */ Space(Context context, AttributeSet attrs)43 public Space(Context context, AttributeSet attrs) { 44 this(context, attrs, 0); 45 } 46 47 /** 48 * {@inheritDoc} 49 */ Space(Context context)50 public Space(Context context) { 51 //noinspection NullableProblems 52 this(context, null); 53 } 54 55 /** 56 * Draw nothing. 57 * 58 * @param canvas an unused parameter. 59 */ 60 @Override draw(Canvas canvas)61 public void draw(Canvas canvas) { 62 } 63 64 /** 65 * Compare to: {@link View#getDefaultSize(int, int)} 66 * If mode is AT_MOST, return the child size instead of the parent size 67 * (unless it is too big). 68 */ getDefaultSize2(int size, int measureSpec)69 private static int getDefaultSize2(int size, int measureSpec) { 70 int result = size; 71 int specMode = MeasureSpec.getMode(measureSpec); 72 int specSize = MeasureSpec.getSize(measureSpec); 73 74 switch (specMode) { 75 case MeasureSpec.UNSPECIFIED: 76 result = size; 77 break; 78 case MeasureSpec.AT_MOST: 79 result = Math.min(size, specSize); 80 break; 81 case MeasureSpec.EXACTLY: 82 result = specSize; 83 break; 84 } 85 return result; 86 } 87 88 @Override onMeasure(int widthMeasureSpec, int heightMeasureSpec)89 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 90 setMeasuredDimension( 91 getDefaultSize2(getSuggestedMinimumWidth(), widthMeasureSpec), 92 getDefaultSize2(getSuggestedMinimumHeight(), heightMeasureSpec)); 93 } 94 } 95