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.FloatRange; import android.annotation.NonNull; import android.os.Parcel; import android.text.ParcelableSpan; import android.text.TextPaint; import android.text.TextUtils; /** * Uniformly scales the size of the text to which it's attached by a certain proportion. * <p> * For example, a <code>RelativeSizeSpan</code> that increases the text size by 50% can be * constructed like this: * <pre>{@code * SpannableString string = new SpannableString("Text with relative size span"); *string.setSpan(new RelativeSizeSpan(1.5f), 10, 24, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);}</pre> * <img src="{@docRoot}reference/android/images/text/style/relativesizespan.png" /> * <figcaption>Text increased by 50% with <code>RelativeSizeSpan</code>.</figcaption> */ public class RelativeSizeSpan extends MetricAffectingSpan implements ParcelableSpan { private final float mProportion; /** * Creates a {@link RelativeSizeSpan} based on a proportion. * * @param proportion the proportion with which the text is scaled. */ public RelativeSizeSpan(@FloatRange(from = 0) float proportion) { mProportion = proportion; } /** * Creates a {@link RelativeSizeSpan} from a parcel. */ public RelativeSizeSpan(@NonNull Parcel src) { mProportion = src.readFloat(); } @Override public int getSpanTypeId() { return getSpanTypeIdInternal(); } /** @hide */ @Override public int getSpanTypeIdInternal() { return TextUtils.RELATIVE_SIZE_SPAN; } @Override public int describeContents() { return 0; } @Override public void writeToParcel(@NonNull Parcel dest, int flags) { writeToParcelInternal(dest, flags); } /** @hide */ @Override public void writeToParcelInternal(@NonNull Parcel dest, int flags) { dest.writeFloat(mProportion); } /** * @return the proportion with which the text size is changed. */ public float getSizeChange() { return mProportion; } @Override public void updateDrawState(@NonNull TextPaint ds) { ds.setTextSize(ds.getTextSize() * mProportion); } @Override public void updateMeasureState(@NonNull TextPaint ds) { ds.setTextSize(ds.getTextSize() * mProportion); } }