1/*
2 * Copyright (C) 2017 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.setupwizardlib.view;
18
19import android.content.Context;
20import android.util.AttributeSet;
21import android.view.View;
22import android.widget.LinearLayout;
23
24import com.android.setupwizardlib.R;
25
26/**
27 * An extension of LinearLayout that automatically switches to vertical orientation when it can't
28 * fit its child views horizontally.
29 *
30 * Modified from {@code com.android.internal.widget.ButtonBarLayout}
31 */
32public class ButtonBarLayout extends LinearLayout {
33
34    private boolean mStacked = false;
35    private int mOriginalPaddingLeft;
36    private int mOriginalPaddingRight;
37
38    public ButtonBarLayout(Context context) {
39        super(context);
40    }
41
42    public ButtonBarLayout(Context context, AttributeSet attrs) {
43        super(context, attrs);
44    }
45
46    @Override
47    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
48        final int widthSize = MeasureSpec.getSize(widthMeasureSpec);
49
50        setStacked(false);
51
52        boolean needsRemeasure = false;
53
54        int initialWidthMeasureSpec = widthMeasureSpec;
55        if (MeasureSpec.getMode(widthMeasureSpec) == MeasureSpec.EXACTLY) {
56            // Measure with WRAP_CONTENT, so that we can compare the measured size with the
57            // available size to see if we need to stack.
58            initialWidthMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
59
60            // We'll need to remeasure again to fill excess space.
61            needsRemeasure = true;
62        }
63
64        super.onMeasure(initialWidthMeasureSpec, heightMeasureSpec);
65
66        if (getMeasuredWidth() > widthSize) {
67            setStacked(true);
68
69            // Measure again in the new orientation.
70            needsRemeasure = true;
71        }
72
73        if (needsRemeasure) {
74            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
75        }
76    }
77
78    private void setStacked(boolean stacked) {
79        if (mStacked == stacked) {
80            return;
81        }
82        mStacked = stacked;
83        int childCount = getChildCount();
84        for (int i = 0; i < childCount; i++) {
85            View child = getChildAt(i);
86            LayoutParams childParams = (LayoutParams) child.getLayoutParams();
87            if (stacked) {
88                child.setTag(R.id.suw_original_weight, childParams.weight);
89                childParams.weight = 0;
90            } else {
91                Float weight = (Float) child.getTag(R.id.suw_original_weight);
92                if (weight != null) {
93                    childParams.weight = weight;
94                }
95            }
96            child.setLayoutParams(childParams);
97        }
98
99        setOrientation(stacked ? LinearLayout.VERTICAL : LinearLayout.HORIZONTAL);
100
101        // Reverse the child order, so that the primary button is towards the top when vertical
102        for (int i = childCount - 1; i >= 0; i--) {
103            bringChildToFront(getChildAt(i));
104        }
105
106        if (stacked) {
107            // HACK: In the default button bar style, the left and right paddings are not
108            // balanced to compensate for different alignment for borderless (left) button and
109            // the raised (right) button. When it's stacked, we want the buttons to be centered,
110            // so we balance out the paddings here.
111            mOriginalPaddingLeft = getPaddingLeft();
112            mOriginalPaddingRight = getPaddingRight();
113            int paddingHorizontal = Math.max(mOriginalPaddingLeft, mOriginalPaddingRight);
114            setPadding(
115                    paddingHorizontal, getPaddingTop(), paddingHorizontal, getPaddingBottom());
116        } else {
117            setPadding(
118                    mOriginalPaddingLeft,
119                    getPaddingTop(),
120                    mOriginalPaddingRight,
121                    getPaddingBottom());
122        }
123    }
124}
125