1/*
2 * Copyright (C) 2014 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.widget;
18
19import android.content.Context;
20import android.graphics.Canvas;
21import android.graphics.Paint;
22import android.graphics.Path;
23import android.util.AttributeSet;
24import android.view.View;
25import android.widget.FrameLayout;
26
27import com.android.camera2.R;
28
29/**
30 * This is a cling widget for settings button. In addition to drawing a cling button
31 * background and overlaying text, it draws a small triangle that points at the
32 * settings button that this cling is for.
33 */
34public class SettingsCling extends FrameLayout {
35    private final int mClingTriangleHeight;
36    private final int mClingTriangleWidth;
37    private final Path mTrianglePath = new Path();
38    private final Paint mClingPaint = new Paint();
39
40    public SettingsCling(Context context, AttributeSet attrs) {
41        super(context, attrs);
42        setWillNotDraw(false);
43        mClingTriangleHeight = getResources().getDimensionPixelSize(
44                R.dimen.settings_cling_triangle_height);
45        mClingTriangleWidth = getResources().getDimensionPixelSize(
46                R.dimen.settings_cling_triangle_width);
47        mClingPaint.setColor(getResources().getColor(R.color.settings_cling_color));
48        mClingPaint.setStyle(Paint.Style.FILL);
49    }
50
51    /**
52     * Updates the current position of the cling based on a reference view. If there
53     * is enough space to lay out the cling on top of the reference view, then have
54     * the cling on top. Otherwise, position the cling underneath the reference view.
55     *
56     * @param referenceView a view that cling uses as a position reference
57     */
58    public void updatePosition(View referenceView) {
59        if (referenceView == null) {
60            return;
61        }
62        // Right align cling:
63        float referenceRight = referenceView.getX() + referenceView.getMeasuredWidth();
64        setTranslationX(referenceRight - getMeasuredWidth());
65
66        float referenceTop = referenceView.getY();
67        if (referenceTop < getMeasuredHeight()) {
68            // Layout cling under reference view.
69            setTranslationY(referenceTop + referenceView.getMeasuredHeight());
70            float triangleStartX = getMeasuredWidth() - referenceView.getMeasuredWidth() / 2;
71            float triangleStartY = 0;
72            mTrianglePath.reset();
73            mTrianglePath.moveTo(triangleStartX, triangleStartY);
74            mTrianglePath.lineTo(triangleStartX - mClingTriangleWidth / 2,
75                    triangleStartY + mClingTriangleHeight);
76            mTrianglePath.lineTo(triangleStartX + mClingTriangleWidth / 2,
77                    triangleStartY + mClingTriangleHeight);
78            mTrianglePath.lineTo(triangleStartX, triangleStartY);
79        } else {
80            // Layout cling on top of reference view.
81            setTranslationY(referenceTop - getMeasuredHeight());
82            float triangleStartX = getMeasuredWidth() - referenceView.getMeasuredWidth() / 2;
83            float triangleStartY = getMeasuredHeight();
84            mTrianglePath.reset();
85            mTrianglePath.moveTo(triangleStartX, triangleStartY);
86            mTrianglePath.lineTo(triangleStartX - mClingTriangleWidth / 2,
87                    triangleStartY - mClingTriangleHeight);
88            mTrianglePath.lineTo(triangleStartX + mClingTriangleWidth / 2,
89                    triangleStartY - mClingTriangleHeight);
90            mTrianglePath.lineTo(triangleStartX, triangleStartY);
91        }
92        invalidate();
93    }
94
95    @Override
96    public void onDraw(Canvas canvas) {
97        super.onDraw(canvas);
98        // Draw triangle.
99        canvas.drawPath(mTrianglePath, mClingPaint);
100    }
101}
102