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.widget; 18 19 import android.content.Context; 20 import android.graphics.Canvas; 21 import android.util.AttributeSet; 22 import android.view.View; 23 24 /** 25 * Space is a lightweight View subclass that may be used to create gaps between components 26 * in general purpose layouts. 27 */ 28 public final class Space extends View { 29 /** 30 * {@inheritDoc} 31 */ Space(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes)32 public Space(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) { 33 super(context, attrs, defStyleAttr, defStyleRes); 34 if (getVisibility() == VISIBLE) { 35 setVisibility(INVISIBLE); 36 } 37 } 38 39 /** 40 * {@inheritDoc} 41 */ Space(Context context, AttributeSet attrs, int defStyleAttr)42 public Space(Context context, AttributeSet attrs, int defStyleAttr) { 43 this(context, attrs, defStyleAttr, 0); 44 } 45 46 /** 47 * {@inheritDoc} 48 */ Space(Context context, AttributeSet attrs)49 public Space(Context context, AttributeSet attrs) { 50 this(context, attrs, 0); 51 } 52 53 /** 54 * {@inheritDoc} 55 */ Space(Context context)56 public Space(Context context) { 57 //noinspection NullableProblems 58 this(context, null); 59 } 60 61 /** 62 * Draw nothing. 63 * 64 * @param canvas an unused parameter. 65 */ 66 @Override draw(Canvas canvas)67 public void draw(Canvas canvas) { 68 } 69 70 /** 71 * Compare to: {@link View#getDefaultSize(int, int)} 72 * If mode is AT_MOST, return the child size instead of the parent size 73 * (unless it is too big). 74 */ getDefaultSize2(int size, int measureSpec)75 private static int getDefaultSize2(int size, int measureSpec) { 76 int result = size; 77 int specMode = MeasureSpec.getMode(measureSpec); 78 int specSize = MeasureSpec.getSize(measureSpec); 79 80 switch (specMode) { 81 case MeasureSpec.UNSPECIFIED: 82 result = size; 83 break; 84 case MeasureSpec.AT_MOST: 85 result = Math.min(size, specSize); 86 break; 87 case MeasureSpec.EXACTLY: 88 result = specSize; 89 break; 90 } 91 return result; 92 } 93 94 @Override onMeasure(int widthMeasureSpec, int heightMeasureSpec)95 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 96 setMeasuredDimension( 97 getDefaultSize2(getSuggestedMinimumWidth(), widthMeasureSpec), 98 getDefaultSize2(getSuggestedMinimumHeight(), heightMeasureSpec)); 99 } 100 } 101