ImageFloatingTextView.java revision 1c72fa0249c364143d0818d129b6dc7f70054752 
1/*
2 * Copyright (C) 2015 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.internal.widget;
18
19import android.annotation.Nullable;
20import android.content.Context;
21import android.text.BoringLayout;
22import android.text.Layout;
23import android.text.StaticLayout;
24import android.text.TextUtils;
25import android.text.method.TransformationMethod;
26import android.util.AttributeSet;
27import android.view.RemotableViewMethod;
28import android.widget.RemoteViews;
29import android.widget.TextView;
30
31import com.android.internal.R;
32
33/**
34 * A TextView that can float around an image on the end.
35 *
36 * @hide
37 */
38@RemoteViews.RemoteView
39public class ImageFloatingTextView extends TextView {
40
41    /** Number of lines from the top to indent */
42    private int mIndentLines;
43
44    /** Resolved layout direction */
45    private int mResolvedDirection = LAYOUT_DIRECTION_UNDEFINED;
46    private int mMaxLinesForHeight = -1;
47    private boolean mFirstMeasure = true;
48    private int mLayoutMaxLines = -1;
49    private boolean mBlockLayouts;
50    private int mImageEndMargin;
51
52    public ImageFloatingTextView(Context context) {
53        this(context, null);
54    }
55
56    public ImageFloatingTextView(Context context, @Nullable AttributeSet attrs) {
57        this(context, attrs, 0);
58    }
59
60    public ImageFloatingTextView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
61        this(context, attrs, defStyleAttr, 0);
62    }
63
64    public ImageFloatingTextView(Context context, AttributeSet attrs, int defStyleAttr,
65            int defStyleRes) {
66        super(context, attrs, defStyleAttr, defStyleRes);
67    }
68
69    @Override
70    protected Layout makeSingleLayout(int wantWidth, BoringLayout.Metrics boring, int ellipsisWidth,
71            Layout.Alignment alignment, boolean shouldEllipsize,
72            TextUtils.TruncateAt effectiveEllipsize, boolean useSaved) {
73        TransformationMethod transformationMethod = getTransformationMethod();
74        CharSequence text = getText();
75        if (transformationMethod != null) {
76            text = transformationMethod.getTransformation(text, this);
77        }
78        text = text == null ? "" : text;
79        StaticLayout.Builder builder = StaticLayout.Builder.obtain(text, 0, text.length(),
80                getPaint(), wantWidth)
81                .setAlignment(alignment)
82                .setTextDirection(getTextDirectionHeuristic())
83                .setLineSpacing(getLineSpacingExtra(), getLineSpacingMultiplier())
84                .setIncludePad(getIncludeFontPadding())
85                .setUseLineSpacingFromFallbacks(true)
86                .setBreakStrategy(Layout.BREAK_STRATEGY_HIGH_QUALITY)
87                .setHyphenationFrequency(Layout.HYPHENATION_FREQUENCY_FULL);
88        int maxLines;
89        if (mMaxLinesForHeight > 0) {
90            maxLines = mMaxLinesForHeight;
91        } else {
92            maxLines = getMaxLines() >= 0 ? getMaxLines() : Integer.MAX_VALUE;
93        }
94        builder.setMaxLines(maxLines);
95        mLayoutMaxLines = maxLines;
96        if (shouldEllipsize) {
97            builder.setEllipsize(effectiveEllipsize)
98                    .setEllipsizedWidth(ellipsisWidth);
99        }
100
101        // we set the endmargin on the requested number of lines.
102        int[] margins = null;
103        if (mIndentLines > 0) {
104            margins = new int[mIndentLines + 1];
105            for (int i = 0; i < mIndentLines; i++) {
106                margins[i] = mImageEndMargin;
107            }
108        }
109        if (mResolvedDirection == LAYOUT_DIRECTION_RTL) {
110            builder.setIndents(margins, null);
111        } else {
112            builder.setIndents(null, margins);
113        }
114
115        return builder.build();
116    }
117
118    @RemotableViewMethod
119    public void setImageEndMargin(int imageEndMargin) {
120        mImageEndMargin = imageEndMargin;
121    }
122
123    @Override
124    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
125        int height = MeasureSpec.getSize(heightMeasureSpec);
126        // Lets calculate how many lines the given measurement allows us.
127        int availableHeight = height - mPaddingTop - mPaddingBottom;
128        int maxLines = availableHeight / getLineHeight();
129        maxLines = Math.max(1, maxLines);
130        if (getMaxLines() > 0) {
131            maxLines = Math.min(getMaxLines(), maxLines);
132        }
133        if (maxLines != mMaxLinesForHeight) {
134            mMaxLinesForHeight = maxLines;
135            if (getLayout() != null && mMaxLinesForHeight != mLayoutMaxLines) {
136                // Invalidate layout.
137                mBlockLayouts = true;
138                setHint(getHint());
139                mBlockLayouts = false;
140            }
141        }
142        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
143    }
144
145    @Override
146    public void requestLayout() {
147        if (!mBlockLayouts) {
148            super.requestLayout();
149        }
150    }
151
152    @Override
153    public void onRtlPropertiesChanged(int layoutDirection) {
154        super.onRtlPropertiesChanged(layoutDirection);
155
156        if (layoutDirection != mResolvedDirection && isLayoutDirectionResolved()) {
157            mResolvedDirection = layoutDirection;
158            if (mIndentLines > 0) {
159                // Invalidate layout.
160                setHint(getHint());
161            }
162        }
163    }
164
165    @RemotableViewMethod
166    public void setHasImage(boolean hasImage) {
167        setNumIndentLines(hasImage ? 2 : 0);
168    }
169
170    /**
171     * @param lines the number of lines at the top that should be indented by indentEnd
172     * @return whether a change was made
173     */
174    public boolean setNumIndentLines(int lines) {
175        if (mIndentLines != lines) {
176            mIndentLines = lines;
177            // Invalidate layout.
178            setHint(getHint());
179            return true;
180        }
181        return false;
182    }
183}
184