1 /* 2 * Copyright (C) 2015 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.v4.widget; 18 19 import android.annotation.SuppressLint; 20 import android.content.Context; 21 import android.graphics.Canvas; 22 import android.util.AttributeSet; 23 import android.view.View; 24 25 /** 26 * Space is a lightweight {@link View} subclass that may be used to create gaps between components 27 * in general purpose layouts. 28 */ 29 public class Space extends View { 30 Space(Context context, AttributeSet attrs, int defStyle)31 public Space(Context context, AttributeSet attrs, int defStyle) { 32 super(context, attrs, defStyle); 33 if (getVisibility() == VISIBLE) { 34 setVisibility(INVISIBLE); 35 } 36 } 37 Space(Context context, AttributeSet attrs)38 public Space(Context context, AttributeSet attrs) { 39 this(context, attrs, 0); 40 } 41 Space(Context context)42 public Space(Context context) { 43 this(context, null); 44 } 45 46 /** 47 * Draw nothing. 48 * 49 * @param canvas an unused parameter. 50 */ 51 @Override 52 @SuppressLint("MissingSuperCall") draw(Canvas canvas)53 public void draw(Canvas canvas) { 54 } 55 56 /** 57 * Compare to: {@link View#getDefaultSize(int, int)} 58 * If mode is AT_MOST, return the child size instead of the parent size 59 * (unless it is too big). 60 */ getDefaultSize2(int size, int measureSpec)61 private static int getDefaultSize2(int size, int measureSpec) { 62 int result = size; 63 int specMode = MeasureSpec.getMode(measureSpec); 64 int specSize = MeasureSpec.getSize(measureSpec); 65 66 switch (specMode) { 67 case MeasureSpec.UNSPECIFIED: 68 result = size; 69 break; 70 case MeasureSpec.AT_MOST: 71 result = Math.min(size, specSize); 72 break; 73 case MeasureSpec.EXACTLY: 74 result = specSize; 75 break; 76 } 77 return result; 78 } 79 80 @Override onMeasure(int widthMeasureSpec, int heightMeasureSpec)81 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 82 setMeasuredDimension( 83 getDefaultSize2(getSuggestedMinimumWidth(), widthMeasureSpec), 84 getDefaultSize2(getSuggestedMinimumHeight(), heightMeasureSpec)); 85 } 86 }