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
17package android.widget;
18
19import android.content.Context;
20import android.graphics.Canvas;
21import android.util.AttributeSet;
22import 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 */
28public final class Space extends View {
29    /**
30     * {@inheritDoc}
31     */
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     */
42    public Space(Context context, AttributeSet attrs, int defStyleAttr) {
43        this(context, attrs, defStyleAttr, 0);
44    }
45
46    /**
47     * {@inheritDoc}
48     */
49    public Space(Context context, AttributeSet attrs) {
50        this(context, attrs, 0);
51    }
52
53    /**
54     * {@inheritDoc}
55     */
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
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     */
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
95    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
96        setMeasuredDimension(
97                getDefaultSize2(getSuggestedMinimumWidth(), widthMeasureSpec),
98                getDefaultSize2(getSuggestedMinimumHeight(), heightMeasureSpec));
99    }
100}
101