自定义EditText,TextView监听是否超过最大行数,显示省略号

1.概述

我们给TextView或者EditTextViwe设置最大行数,超过最大行时我们没有相应的回调,这样当想处理超过最大行数的逻辑时就没有相应的方法,下面我自定义了有监听超过最大行数的EditText和TextView

效果图

下面的效果图textView设置成输入editTextView的字体,他们的最大行数都设置2行,超过最大行数和不超过分别设置成不同的字体颜色

图



效果图代码

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
>
<com.geely.mars.mvpdemo.activity.view.OverLineEdixView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/editext"
android:textSize="30sp"
android:maxLines="2"
android:ellipsize="end"/>
<com.geely.mars.mvpdemo.activity.view.OverLineTextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:maxLines="2"
android:textSize="30sp"
android:id="@+id/textview"
android:ellipsize="end"/>
</LinearLayout>

package com.geely.mars.mvpdemo.activity.view;

import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.text.Editable;
import android.text.TextWatcher;

import com.geely.mars.mvpdemo.R;

public class ActMain extends Activity {

private OverLineEdixView edixView;
private OverLineTextView textView;

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.act_main);
edixView = findViewById(R.id.editext);
textView = findViewById(R.id.textview);
initView();
setListener();
}

private void initView() {
edixView.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

}

@Override
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {

}

@Override
public void afterTextChanged(Editable editable) {
textView.setText(editable.toString());
}
});
}

private void setListener() {
edixView.setOnOverLineChangerListener(new OverLineEdixView.OnOverLineChangerListener() {
@Override
public void onOverLine(boolean inOverLine) {
if (inOverLine){
edixView.setTextColor(Color.parseColor("#ff0000"));
}else {
edixView.setTextColor(Color.BLACK);
}
}
});
textView.setOnOverLineChangerListener(new OverLineTextView.OnOverLineChangerListener() {
@Override
public void onOverLine(boolean inOverLine) {
if (inOverLine){
textView.setTextColor(Color.RED);
}else {
textView.setTextColor(Color.parseColor("#00ff00"));
}

}
});
}

}

3.具体的实现代码

代码比较简答 就直接贴代码,关键地方有相关注释

OverLineEdixView

package com.geely.mars.mvpdemo.activity.view;

import android.annotation.TargetApi;
import android.content.Context;
import android.graphics.Canvas;
import android.os.Build;
import android.support.v7.widget.AppCompatEditText;
import android.text.Layout;
import android.util.AttributeSet;
import android.view.ViewTreeObserver;

public class OverLineEdixView extends android.support.v7.widget.AppCompatEditText {
private OnOverLineChangerListener listener;
private AppCompatEditText normalStatu;

public OverLineEdixView(Context context) {
super(context);
init();
}

public OverLineEdixView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}

public OverLineEdixView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
private void init() {
normalStatu=this;
getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
if (listener!=null){
listener.onOverLine(isOverLine());
}
}
});
}

@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (listener!=null){
listener.onOverLine(isOverLine());
}
}

@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
private boolean isOverLine() {
int lineCount = getLineCount();
int maxLines = getMaxLines();
return lineCount > maxLines;
}

interface OnOverLineChangerListener{
void onOverLine(boolean inOverLine);
}
public void setOnOverLineChangerListener(OnOverLineChangerListener listener){
this.listener=listener;
}

}

OverLineTextView

package com.geely.mars.mvpdemo.activity.view;

import android.annotation.TargetApi;
import android.content.Context;
import android.graphics.Canvas;
import android.os.Build;
import android.text.Layout;
import android.util.AttributeSet;
import android.view.ViewTreeObserver;
import android.widget.TextView;

import java.lang.reflect.Field;

public class OverLineTextView extends TextView {
private boolean isOverSize;
private OnOverLineChangerListener listener;

public OverLineTextView(Context context) {
super(context);
init();
}

public OverLineTextView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}

@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
private void init() {
// invalidate when layout end
getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {

@Override
public void onGlobalLayout() {
if (listener != null) {
listener.onOverLine(checkOverLine());
}
}
});

}

public boolean isOverSize() {
return isOverSize;
}

@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (listener != null) {
listener.onOverLine(checkOverLine());
}
}

public boolean checkOverLine() {
//获取当前textview的行数
int maxLine = getLineCount();
try {
Field field = getClass().getSuperclass().getDeclaredField("mLayout");
field.setAccessible(true);
Layout mLayout = (Layout) field.get(this);
if (mLayout == null) {
return false;
}
//mLayout.getEllipsisCount获取textView对应行数索引出的省略的字符数,没有省略返回0
isOverSize = mLayout.getEllipsisCount(maxLine - 1) > 0 ? true : false;
} catch (NoSuchFieldException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (IllegalArgumentException e) {
e.printStackTrace();
}
return isOverSize;
}
interface OnOverLineChangerListener{
void onOverLine(boolean inOverLine);
}
public void setOnOverLineChangerListener(OnOverLineChangerListener listener){
this.listener=listener;
}
}