Java tutorial
/* * 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.DrawableRes; import android.annotation.NonNull; import android.annotation.Nullable; import android.annotation.UnsupportedAppUsage; import android.content.Context; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.drawable.BitmapDrawable; import android.graphics.drawable.Drawable; import android.net.Uri; import android.util.Log; import java.io.InputStream; /** * 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. The drawable can be constructed from * varied sources: * <ul> * <li>{@link Bitmap} - see {@link #ImageSpan(Context, Bitmap)} and * {@link #ImageSpan(Context, Bitmap, int)} * </li> * <li>{@link Drawable} - see {@link #ImageSpan(Drawable, int)}</li> * <li>resource id - see {@link #ImageSpan(Context, int, int)}</li> * <li>{@link Uri} - see {@link #ImageSpan(Context, Uri, int)}</li> * </ul> * The default value for the vertical alignment is {@link DynamicDrawableSpan#ALIGN_BOTTOM} * <p> * For example, an <code>ImagedSpan</code> can be used like this: * <pre> * SpannableString string = SpannableString("Bottom: span.\nBaseline: span."); * // using the default alignment: ALIGN_BOTTOM * string.setSpan(ImageSpan(this, R.mipmap.ic_launcher), 7, 8, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE); * string.setSpan(ImageSpan(this, R.mipmap.ic_launcher, DynamicDrawableSpan.ALIGN_BASELINE), * 22, 23, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE); * </pre> * <img src="{@docRoot}reference/android/images/text/style/imagespan.png" /> * <figcaption>Text with <code>ImageSpan</code>s aligned bottom and baseline.</figcaption> */ public class ImageSpan extends DynamicDrawableSpan { @Nullable @UnsupportedAppUsage private Drawable mDrawable; @Nullable private Uri mContentUri; @DrawableRes private int mResourceId; @Nullable private Context mContext; @Nullable private String mSource; /** * @deprecated Use {@link #ImageSpan(Context, Bitmap)} instead. */ @Deprecated public ImageSpan(@NonNull Bitmap b) { this(null, b, ALIGN_BOTTOM); } /** * @deprecated Use {@link #ImageSpan(Context, Bitmap, int)} instead. */ @Deprecated public ImageSpan(@NonNull Bitmap b, int verticalAlignment) { this(null, b, verticalAlignment); } /** * Constructs an {@link ImageSpan} from a {@link Context} and a {@link Bitmap} with the default * alignment {@link DynamicDrawableSpan#ALIGN_BOTTOM} * * @param context context used to create a drawable from {@param bitmap} based on the display * metrics of the resources * @param bitmap bitmap to be rendered */ public ImageSpan(@NonNull Context context, @NonNull Bitmap bitmap) { this(context, bitmap, ALIGN_BOTTOM); } /** * Constructs an {@link ImageSpan} from a {@link Context}, a {@link Bitmap} and a vertical * alignment. * * @param context context used to create a drawable from {@param bitmap} based on * the display metrics of the resources * @param bitmap bitmap to be rendered * @param verticalAlignment one of {@link DynamicDrawableSpan#ALIGN_BOTTOM} or * {@link DynamicDrawableSpan#ALIGN_BASELINE} */ public ImageSpan(@NonNull Context context, @NonNull Bitmap bitmap, int verticalAlignment) { super(verticalAlignment); mContext = context; mDrawable = context != null ? new BitmapDrawable(context.getResources(), bitmap) : new BitmapDrawable(bitmap); int width = mDrawable.getIntrinsicWidth(); int height = mDrawable.getIntrinsicHeight(); mDrawable.setBounds(0, 0, width > 0 ? width : 0, height > 0 ? height : 0); } /** * Constructs an {@link ImageSpan} from a drawable with the default * alignment {@link DynamicDrawableSpan#ALIGN_BOTTOM}. * * @param drawable drawable to be rendered */ public ImageSpan(@NonNull Drawable drawable) { this(drawable, ALIGN_BOTTOM); } /** * Constructs an {@link ImageSpan} from a drawable and a vertical alignment. * * @param drawable drawable to be rendered * @param verticalAlignment one of {@link DynamicDrawableSpan#ALIGN_BOTTOM} or * {@link DynamicDrawableSpan#ALIGN_BASELINE} */ public ImageSpan(@NonNull Drawable drawable, int verticalAlignment) { super(verticalAlignment); mDrawable = drawable; } /** * Constructs an {@link ImageSpan} from a drawable and a source with the default * alignment {@link DynamicDrawableSpan#ALIGN_BOTTOM} * * @param drawable drawable to be rendered * @param source drawable's Uri source */ public ImageSpan(@NonNull Drawable drawable, @NonNull String source) { this(drawable, source, ALIGN_BOTTOM); } /** * Constructs an {@link ImageSpan} from a drawable, a source and a vertical alignment. * * @param drawable drawable to be rendered * @param source drawable's uri source * @param verticalAlignment one of {@link DynamicDrawableSpan#ALIGN_BOTTOM} or * {@link DynamicDrawableSpan#ALIGN_BASELINE} */ public ImageSpan(@NonNull Drawable drawable, @NonNull String source, int verticalAlignment) { super(verticalAlignment); mDrawable = drawable; mSource = source; } /** * Constructs an {@link ImageSpan} from a {@link Context} and a {@link Uri} with the default * alignment {@link DynamicDrawableSpan#ALIGN_BOTTOM}. The Uri source can be retrieved via * {@link #getSource()} * * @param context context used to create a drawable from {@param bitmap} based on the display * metrics of the resources * @param uri {@link Uri} used to construct the drawable that will be rendered */ public ImageSpan(@NonNull Context context, @NonNull Uri uri) { this(context, uri, ALIGN_BOTTOM); } /** * Constructs an {@link ImageSpan} from a {@link Context}, a {@link Uri} and a vertical * alignment. The Uri source can be retrieved via {@link #getSource()} * * @param context context used to create a drawable from {@param bitmap} based on * the display * metrics of the resources * @param uri {@link Uri} used to construct the drawable that will be rendered. * @param verticalAlignment one of {@link DynamicDrawableSpan#ALIGN_BOTTOM} or * {@link DynamicDrawableSpan#ALIGN_BASELINE} */ public ImageSpan(@NonNull Context context, @NonNull Uri uri, int verticalAlignment) { super(verticalAlignment); mContext = context; mContentUri = uri; mSource = uri.toString(); } /** * Constructs an {@link ImageSpan} from a {@link Context} and a resource id with the default * alignment {@link DynamicDrawableSpan#ALIGN_BOTTOM} * * @param context context used to retrieve the drawable from resources * @param resourceId drawable resource id based on which the drawable is retrieved */ public ImageSpan(@NonNull Context context, @DrawableRes int resourceId) { this(context, resourceId, ALIGN_BOTTOM); } /** * Constructs an {@link ImageSpan} from a {@link Context}, a resource id and a vertical * alignment. * * @param context context used to retrieve the drawable from resources * @param resourceId drawable resource id based on which the drawable is retrieved. * @param verticalAlignment one of {@link DynamicDrawableSpan#ALIGN_BOTTOM} or * {@link DynamicDrawableSpan#ALIGN_BASELINE} */ public ImageSpan(@NonNull Context context, @DrawableRes int resourceId, int verticalAlignment) { super(verticalAlignment); mContext = context; mResourceId = resourceId; } @Override public Drawable getDrawable() { Drawable drawable = null; if (mDrawable != null) { drawable = mDrawable; } else if (mContentUri != null) { Bitmap bitmap = null; try { InputStream is = mContext.getContentResolver().openInputStream(mContentUri); bitmap = BitmapFactory.decodeStream(is); drawable = new BitmapDrawable(mContext.getResources(), bitmap); drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight()); is.close(); } catch (Exception e) { Log.e("ImageSpan", "Failed to loaded content " + mContentUri, e); } } else { try { drawable = mContext.getDrawable(mResourceId); drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight()); } catch (Exception e) { Log.e("ImageSpan", "Unable to find resource: " + mResourceId); } } return drawable; } /** * Returns the source string that was saved during construction. * * @return the source string that was saved during construction * @see #ImageSpan(Drawable, String) * @see #ImageSpan(Context, Uri) */ @Nullable public String getSource() { return mSource; } }