/*
* Created by LuaView.
* Copyright (c) 2017, Alibaba Group. All rights reserved.
*
* This source code is licensed under the MIT.
* For the full copyright and license information,please view the LICENSE file in the root directory of this source tree.
*/
package com.taobao.luaview.util;
import android.annotation.TargetApi;
import android.content.Context;
import android.content.res.Resources;
import android.os.Build;
import android.text.Layout;
import android.text.StaticLayout;
import android.text.TextPaint;
import android.text.method.SingleLineTransformationMethod;
import android.text.method.TransformationMethod;
import android.util.DisplayMetrics;
import android.util.Log;
import android.util.TypedValue;
import android.view.ViewGroup;
import android.widget.TextView;
/**
* 文字相关的工具类
*
* @author song
* @date 15/10/22
*/
public class TextUtil {
private static final String TAG = "TextUtil";
private static final boolean SPEW = false;
// Minimum size of the text in pixels
private static final int DEFAULT_MIN_TEXT_SIZE = 8; //sp
// How precise we want to be when reaching the target textWidth size
private static final float DEFAULT_PRECISION = 0.5f;
/**
* 使文字大小适应frame
*
* @param view
*/
public static void adjustTextSize(TextView view) {
final Context context = view.getContext();
float scaledDensity = context.getResources().getDisplayMetrics().scaledDensity;
TextPaint paint = new TextPaint();
int maxLines = getMaxLines(view);
float minTextSize = scaledDensity * DEFAULT_MIN_TEXT_SIZE;
float maxTextSize = view.getTextSize();
float precision = DEFAULT_PRECISION;
adjustTextSize(view, paint, minTextSize, maxTextSize, maxLines, precision);
}
/**
* 改变外框大小，适应文字
* 如果当前文字只有一行，则缩到外框适应文字大小
* 如果文字有多行，则宽度不变，缩小高度到适应文字大小
* 文字外框的位置不变
*
* @param view
*/
@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
public static void adjustSize(TextView view) {
if (view != null && view.getLayoutParams() != null) {
/*
//更好的实现方式，但是ios那边不支持这种方式
ViewGroup.LayoutParams layoutParams = view.getLayoutParams();
layoutParams.width = ViewGroup.LayoutParams.WRAP_CONTENT;
layoutParams.height = ViewGroup.LayoutParams.WRAP_CONTENT;
view.setLayoutParams(layoutParams);*/
// 废弃的实现方式，使用WRAP_CONTENT最简单，且这种方式算出来的width有bug
// @Deprecated
/*int lineCount = Math.min(view.getLineCount(), getMaxLines(view));
int width, height;
if (lineCount > 1) {//多行，宽度不变，改变高度
width = view.getWidth();
height = view.getLineHeight() * lineCount + view.getPaddingTop() + view.getPaddingBottom();
} else {//一行，改变宽度&高度
final Paint paint = view.getPaint();
width = (int) paint.measureText(view.getText().toString()) + view.getPaddingLeft() + view.getPaddingRight();
height = view.getLineHeight() + view.getPaddingTop() + view.getPaddingBottom();
}*/
int lineCount = Math.min(view.getLineCount(), getMaxLines(view));
float width, height;
if (lineCount > 1) {//多行，宽度不变，改变高度
width = view.getWidth();
height = view.getLineHeight() * lineCount + view.getPaddingTop() + view.getPaddingBottom();
} else {//一行，改变宽度&高度
width = view.getPaddingLeft() + Layout.getDesiredWidth(view.getText(), view.getPaint()) + view.getPaddingRight();
height = view.getLineHeight() + view.getPaddingTop() + view.getPaddingBottom();
}
if (view.getLayoutParams() != null) {
ViewGroup.LayoutParams layoutParams = view.getLayoutParams();
layoutParams.width = (int) width;
layoutParams.height = (int) height;
view.setLayoutParams(layoutParams);
}
}
}
/**
* Re-sizes the textSize of the TextView so that the text fits within the bounds of the View.
*/
private static void adjustTextSize(TextView view, TextPaint paint, float minTextSize, float maxTextSize, int maxLines, float precision) {
if (maxLines <= 0 || maxLines == Integer.MAX_VALUE) {
// Don't auto-size since there's no limit on lines.
return;
}
int targetWidth = view.getWidth() - view.getPaddingLeft() - view.getPaddingRight();
if (targetWidth <= 0) {
return;
}
CharSequence text = view.getText();
TransformationMethod method = view.getTransformationMethod();
if (method != null) {
text = method.getTransformation(text, view);
}
Context context = view.getContext();
Resources r = Resources.getSystem();
DisplayMetrics displayMetrics;
float size = maxTextSize;
float high = size;
float low = 0;
if (context != null) {
r = context.getResources();
}
displayMetrics = r.getDisplayMetrics();
paint.set(view.getPaint());
paint.setTextSize(size);
if ((maxLines == 1 && paint.measureText(text, 0, text.length()) > targetWidth)
|| getLineCount(text, paint, size, targetWidth, displayMetrics) > maxLines) {
size = getAutofitTextSize(text, paint, targetWidth, maxLines, low, high, precision, displayMetrics);
}
if (size < minTextSize) {
size = minTextSize;
}
view.setTextSize(TypedValue.COMPLEX_UNIT_PX, size);
}
/**
* Recursive binary search to find the best size for the text.
*/
private static float getAutofitTextSize(CharSequence text, TextPaint paint, float targetWidth, int maxLines, float low, float high, float precision, DisplayMetrics displayMetrics) {
float mid = (low + high) / 2.0f;
int lineCount = 1;
StaticLayout layout = null;
paint.setTextSize(TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_PX, mid, displayMetrics));
if (maxLines != 1) {
layout = new StaticLayout(text, paint, (int) targetWidth, Layout.Alignment.ALIGN_NORMAL, 1.0f, 0.0f, true);
lineCount = layout.getLineCount();
}
if (SPEW)
Log.d(TAG, "low=" + low + " high=" + high + " mid=" + mid + " target=" + targetWidth + " maxLines=" + maxLines + " lineCount=" + lineCount);
if (lineCount > maxLines) {
// For the case that `text` has more newline characters than `maxLines`.
if ((high - low) < precision) {
return low;
}
return getAutofitTextSize(text, paint, targetWidth, maxLines, low, mid, precision, displayMetrics);
} else if (lineCount < maxLines) {
return getAutofitTextSize(text, paint, targetWidth, maxLines, mid, high, precision, displayMetrics);
} else {
float maxLineWidth = 0;
if (maxLines == 1) {
maxLineWidth = paint.measureText(text, 0, text.length());
} else {
for (int i = 0; i < lineCount; i++) {
if (layout.getLineWidth(i) > maxLineWidth) {
maxLineWidth = layout.getLineWidth(i);
}
}
}
if ((high - low) < precision) {
return low;
} else if (maxLineWidth > targetWidth) {
return getAutofitTextSize(text, paint, targetWidth, maxLines, low, mid, precision, displayMetrics);
} else if (maxLineWidth < targetWidth) {
return getAutofitTextSize(text, paint, targetWidth, maxLines, mid, high, precision, displayMetrics);
} else {
return mid;
}
}
}
private static int getLineCount(CharSequence text, TextPaint paint, float size, float width, DisplayMetrics displayMetrics) {
paint.setTextSize(TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_PX, size, displayMetrics));
StaticLayout layout = new StaticLayout(text, paint, (int) width, Layout.Alignment.ALIGN_NORMAL, 1.0f, 0.0f, true);
return layout.getLineCount();
}
private static int getMaxLines(TextView view) {
int maxLines = -1; // No limit (Integer.MAX_VALUE also means no limit)
TransformationMethod method = view.getTransformationMethod();
if (method != null && method instanceof SingleLineTransformationMethod) {
maxLines = 1;
} else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
// setMaxLines() and getMaxLines() are only available on android-16+
maxLines = view.getMaxLines();
}
return maxLines;
}
}