EvenlySpacedLayout.java revision af7f98026f1564d7a4f9c8084bba763ec1698e04 
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
17package com.android.camera;
18
19import com.android.gallery.R;
20
21import android.content.Context;
22import android.content.res.TypedArray;
23import android.util.AttributeSet;
24import android.view.View;
25import android.view.ViewGroup;
26
27//
28// This is a layout which makes the children even spaced.
29// Currently it does not consider the padding parameters.
30//
31public class EvenlySpacedLayout extends ViewGroup {
32    private boolean mHorizontal;
33
34    // Wheather we keep the space in both ends of the layout
35    private boolean mKeepEndSpace;
36
37    public EvenlySpacedLayout(Context context, AttributeSet attrs) {
38        super(context, attrs);
39        TypedArray a = context.obtainStyledAttributes(
40                attrs, R.styleable.EvenlySpacedLayout, 0, 0);
41        mHorizontal = (0 == a.getInt(
42                R.styleable.EvenlySpacedLayout_orientation, 0));
43        mKeepEndSpace = a.getBoolean(
44                R.styleable.EvenlySpacedLayout_keepEndSpace, true);
45        a.recycle();
46    }
47
48    @Override
49    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
50        int count = getChildCount();
51        int width = 0;
52        int height = 0;
53        for (int i = 0; i < count; i++) {
54            View child = getChildAt(i);
55            if (child.getVisibility() == GONE) continue;
56            measureChild(child, widthMeasureSpec, heightMeasureSpec);
57            if (mHorizontal) {
58                width += child.getMeasuredWidth();
59                height = Math.max(height, child.getMeasuredHeight());
60            } else {
61                height += child.getMeasuredHeight();
62                width = Math.max(width, child.getMeasuredWidth());
63            }
64        }
65        setMeasuredDimension(resolveSize(width, widthMeasureSpec),
66                resolveSize(height, heightMeasureSpec));
67    }
68
69    private void layoutHorizontal(boolean changed, int l, int t, int r, int b) {
70        int count = getChildCount();
71
72        int usedWidth = 0;
73        int usedChildren = 0;
74        for (int i = 0; i < count; i++) {
75            View child = getChildAt(i);
76            if (child.getVisibility() == GONE) continue;
77            usedWidth += child.getMeasuredWidth();
78            ++usedChildren;
79        }
80
81        int spacing = (r - l - usedWidth) /
82                (mKeepEndSpace ? (usedChildren + 1) : (usedChildren - 1));
83        int left = mKeepEndSpace ? spacing : 0;
84        int top = 0;
85        for (int i = 0; i < count; i++) {
86            View child = getChildAt(i);
87            if (child.getVisibility() == GONE) continue;
88            int w = child.getMeasuredWidth();
89            int h = child.getMeasuredHeight();
90            child.layout(left, top, left + w, top + h);
91            left += w;
92            left += spacing;
93        }
94    }
95
96    private void layoutVertical(boolean changed, int l, int t, int r, int b) {
97        int count = getChildCount();
98
99        int usedHeight = 0;
100        int usedChildren = 0;
101        for (int i = 0; i < count; i++) {
102            View child = getChildAt(i);
103            if (child.getVisibility() == GONE) continue;
104            usedHeight += child.getMeasuredHeight();
105            ++usedChildren;
106        }
107
108        int spacing = (b - t - usedHeight) /
109                (mKeepEndSpace ? (usedChildren + 1) : (usedChildren - 1));
110        int top = mKeepEndSpace ? spacing : 0;
111        int left = 0;
112        for (int i = 0; i < count; i++) {
113            View child = getChildAt(i);
114            if (child.getVisibility() == GONE) continue;
115            int w = child.getMeasuredWidth();
116            int h = child.getMeasuredHeight();
117            child.layout(left, top, left + w, top + h);
118            top += h;
119            top += spacing;
120        }
121    }
122
123    @Override
124    protected void onLayout(boolean changed, int l, int t, int r, int b) {
125        if (mHorizontal) {
126            layoutHorizontal(changed, l, t, r, b);
127        } else {
128            layoutVertical(changed, l, t, r, b);
129        }
130    }
131}
132