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/*
* Copyright (C) 2006 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.text.style;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import java.lang.ref.WeakReference;
/**
*
*/
public abstract class DynamicDrawableSpan extends ReplacementSpan {
private static final String TAG = "DynamicDrawableSpan";
/**
* A constant indicating that the bottom of this span should be aligned
* with the bottom of the surrounding text, i.e., at the same level as the
* lowest descender in the text.
*/
public static final int ALIGN_BOTTOM = 0;
/**
* A constant indicating that the bottom of this span should be aligned
* with the baseline of the surrounding text.
*/
public static final int ALIGN_BASELINE = 1;
protected final int mVerticalAlignment;
public DynamicDrawableSpan() {
mVerticalAlignment = ALIGN_BOTTOM;
}
/**
* @param verticalAlignment one of {@link #ALIGN_BOTTOM} or {@link #ALIGN_BASELINE}.
*/
protected DynamicDrawableSpan(int verticalAlignment) {
mVerticalAlignment = verticalAlignment;
}
/**
* Returns the vertical alignment of this span, one of {@link #ALIGN_BOTTOM} or
* {@link #ALIGN_BASELINE}.
*/
public int getVerticalAlignment() {
return mVerticalAlignment;
}
/**
* Your subclass must implement this method to provide the bitmap
* to be drawn. The dimensions of the bitmap must be the same
* from each call to the next.
*/
public abstract Drawable getDrawable();
@Override
public int getSize(Paint paint, CharSequence text,
int start, int end,
Paint.FontMetricsInt fm) {
Drawable d = getCachedDrawable();
Rect rect = d.getBounds();
if (fm != null) {
fm.ascent = -rect.bottom;
fm.descent = 0;
fm.top = fm.ascent;
fm.bottom = 0;
}
return rect.right;
}
@Override
public void draw(Canvas canvas, CharSequence text,
int start, int end, float x,
int top, int y, int bottom, Paint paint) {
Drawable b = getCachedDrawable();
canvas.save();
int transY = bottom - b.getBounds().bottom;
if (mVerticalAlignment == ALIGN_BASELINE) {
transY -= paint.getFontMetricsInt().descent;
}
canvas.translate(x, transY);
b.draw(canvas);
canvas.restore();
}
private Drawable getCachedDrawable() {
WeakReference<Drawable> wr = mDrawableRef;
Drawable d = null;
if (wr != null)
d = wr.get();
if (d == null) {
d = getDrawable();
mDrawableRef = new WeakReference<Drawable>(d);
}
return d;
}
private WeakReference<Drawable> mDrawableRef;
}
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