1/*
2 * Copyright (C) 2017 The Android Open Source Project
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 *      http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 *
15 *
16 */
17
18package com.android.settings.graph;
19
20import android.annotation.Nullable;
21import android.content.Context;
22import android.support.annotation.VisibleForTesting;
23import android.util.AttributeSet;
24import android.view.Gravity;
25import android.view.View;
26import android.widget.LinearLayout;
27
28import com.android.settingslib.R;
29
30/**
31 * An extension of LinearLayout that automatically switches to vertical
32 * orientation when it can't fit its child views horizontally.
33 *
34 * Main logic in this class comes from {@link android.support.v7.widget.ButtonBarLayout}.
35 * Compared with {@link android.support.v7.widget.ButtonBarLayout}, this layout won't reverse
36 * children's order and won't update the minimum height
37 */
38public class BottomLabelLayout extends LinearLayout {
39    private static final String TAG = "BottomLabelLayout";
40
41    public BottomLabelLayout(Context context,
42            @Nullable 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        final boolean isStacked = isStacked();
50        boolean needsRemeasure = false;
51
52        // If we're not stacked, make sure the measure spec is AT_MOST rather
53        // than EXACTLY. This ensures that we'll still get TOO_SMALL so that we
54        // know to stack the buttons.
55        final int initialWidthMeasureSpec;
56        if (!isStacked && MeasureSpec.getMode(widthMeasureSpec) == MeasureSpec.EXACTLY) {
57            initialWidthMeasureSpec = MeasureSpec.makeMeasureSpec(widthSize, MeasureSpec.AT_MOST);
58
59            // We'll need to remeasure again to fill excess space.
60            needsRemeasure = true;
61        } else {
62            initialWidthMeasureSpec = widthMeasureSpec;
63        }
64
65        super.onMeasure(initialWidthMeasureSpec, heightMeasureSpec);
66        if (!isStacked) {
67            final int measuredWidth = getMeasuredWidthAndState();
68            final int measuredWidthState = measuredWidth & View.MEASURED_STATE_MASK;
69
70            if (measuredWidthState == View.MEASURED_STATE_TOO_SMALL) {
71                setStacked(true);
72                // Measure again in the new orientation.
73                needsRemeasure = true;
74            }
75        }
76
77        if (needsRemeasure) {
78            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
79        }
80
81    }
82
83    @VisibleForTesting
84    void setStacked(boolean stacked) {
85        setOrientation(stacked ? LinearLayout.VERTICAL : LinearLayout.HORIZONTAL);
86        setGravity(stacked ? Gravity.START : Gravity.BOTTOM);
87
88        final View spacer = findViewById(R.id.spacer);
89        if (spacer != null) {
90            spacer.setVisibility(stacked ? View.GONE : View.VISIBLE);
91        }
92    }
93
94    private boolean isStacked() {
95        return getOrientation() == LinearLayout.VERTICAL;
96    }
97}
98