| /* |
| * 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.annotation.IntRange; |
| import android.annotation.NonNull; |
| import android.annotation.Nullable; |
| import android.annotation.UnsupportedAppUsage; |
| import android.graphics.Canvas; |
| import android.graphics.Paint; |
| import android.graphics.Rect; |
| import android.graphics.drawable.Drawable; |
| |
| import java.lang.ref.WeakReference; |
| |
| /** |
| * Span that replaces the text it's attached to with a {@link Drawable} that can be aligned with |
| * the bottom or with the baseline of the surrounding text. |
| * <p> |
| * For an implementation that constructs the drawable from various sources (<code>Bitmap</code>, |
| * <code>Drawable</code>, resource id or <code>Uri</code>) use {@link ImageSpan}. |
| * <p> |
| * A simple implementation of <code>DynamicDrawableSpan</code> that uses drawables from resources |
| * looks like this: |
| * <pre> |
| * class MyDynamicDrawableSpan extends DynamicDrawableSpan { |
| * |
| * private final Context mContext; |
| * private final int mResourceId; |
| * |
| * public MyDynamicDrawableSpan(Context context, @DrawableRes int resourceId) { |
| * mContext = context; |
| * mResourceId = resourceId; |
| * } |
| * |
| * {@literal @}Override |
| * public Drawable getDrawable() { |
| * Drawable drawable = mContext.getDrawable(mResourceId); |
| * drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight()); |
| * return drawable; |
| * } |
| * }</pre> |
| * The class can be used like this: |
| * <pre> |
| * SpannableString string = new SpannableString("Text with a drawable span"); |
| * string.setSpan(new MyDynamicDrawableSpan(context, R.mipmap.ic_launcher), 12, 20, Spanned |
| * .SPAN_EXCLUSIVE_EXCLUSIVE);</pre> |
| * <img src="{@docRoot}reference/android/images/text/style/dynamicdrawablespan.png" /> |
| * <figcaption>Replacing text with a drawable.</figcaption> |
| */ |
| public abstract class DynamicDrawableSpan extends ReplacementSpan { |
| |
| /** |
| * 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; |
| |
| @UnsupportedAppUsage |
| private WeakReference<Drawable> mDrawableRef; |
| |
| /** |
| * Creates a {@link DynamicDrawableSpan}. The default vertical alignment is |
| * {@link #ALIGN_BOTTOM} |
| */ |
| public DynamicDrawableSpan() { |
| mVerticalAlignment = ALIGN_BOTTOM; |
| } |
| |
| /** |
| * Creates a {@link DynamicDrawableSpan} based on a vertical alignment.\ |
| * |
| * @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(@NonNull Paint paint, CharSequence text, |
| @IntRange(from = 0) int start, @IntRange(from = 0) int end, |
| @Nullable 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(@NonNull Canvas canvas, CharSequence text, |
| @IntRange(from = 0) int start, @IntRange(from = 0) int end, float x, |
| int top, int y, int bottom, @NonNull 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; |
| } |
| } |
| |