实现简单文本编辑器_利用基于监听的事件处理方式实现简单文本编辑器,分别实现字体颜色、大小样式变化

利用基于监听的事件处理方式实现简单文本编辑器，分别实现字体颜色、大小样式变化以及文本重命名的四种功能，这四种功能要求分别用内部类、外部类、类自身和匿名内部类四种形式实现，其中重点掌握匿名内部类的使用。

实现代码：

MainActivity：

package com.example.shijianchuli;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import android.content.DialogInterface;
import android.graphics.Color;
import android.graphics.Typeface;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity implements View.OnClickListener{
    private Button red,green,blue;
    private TextView testText;
    private Button bigger,smaller;
    private Button bold,italic,moren;
    private boolean isItalic=false,isBold=false;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        testText = (TextView) findViewById(R.id.testTest);
        red = (Button) findViewById(R.id.red);
        green = (Button) findViewById(R.id.green);
        blue = (Button) findViewById(R.id.blue);
        ColorListner myColorLister = new ColorListner();
        red.setOnClickListener(myColorLister);
        green.setOnClickListener(myColorLister);
        blue.setOnClickListener(myColorLister);
        testText.setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View v) {
                AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
                builder.setTitle("请输入新的内容");
                builder.setIcon(R.mipmap.ic_launcher);
                final EditText contentText = new EditText(MainActivity.this);
                builder.setView(contentText);
               builder.setPositiveButton("确定", new DialogInterface.OnClickListener(){
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        testText.setText(contentText.getText().toString());
                    }
                });
                builder.setNegativeButton("取消", null);
                builder.create().show();
                return false;}
        });
        bigger=(Button)findViewById(R.id.bigger);
        smaller=(Button)findViewById(R.id.smaller);
        SizeListener mysizeListener=new SizeListener(testText);
        bigger.setOnClickListener(mysizeListener);
        smaller.setOnClickListener(mysizeListener);
        testText.setTypeface(Typeface.DEFAULT);
        bold=(Button)findViewById(R.id.bold);
        italic=(Button)findViewById(R.id.italic);
        moren=(Button)findViewById(R.id.moren);
        italic.setOnClickListener(this);
        bold.setOnClickListener(this);
        moren.setOnClickListener(this);
    }
    private class ColorListner implements View.OnClickListener{
        public void onClick(View v){
            switch (v.getId()){
                case R.id.red:
                    testText.setTextColor(Color.RED);break;
                case  R.id.blue:
                    testText.setTextColor(Color.BLUE);break;
                case R.id.green:
                    testText.setTextColor(Color.GREEN);break;
                default:break;  
} 
}
    }
    public void onClick(View v){
        switch (v.getId()){
            case R.id.italic:
                isItalic=!isItalic;
                break;
            case R.id.bold:
                isBold=!isBold;
                break;
            case R.id.moren:
                isItalic=false;
                isBold=false;
                break;
            default:
                break;
        }
        if(isItalic){
            if(isBold){
                testText.setTypeface(Typeface.MONOSPACE,Typeface.BOLD_ITALIC);
            }else {
                testText.setTypeface(Typeface.MONOSPACE,Typeface.ITALIC);
            }
        }else {
            if(isBold){
                testText.setTypeface(Typeface.MONOSPACE,Typeface.BOLD);
            }else {
                testText.setTypeface(Typeface.MONOSPACE,Typeface.NORMAL);
            }
        }
    }
}
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SizeListener:

package com.example.shijianchuli;
import android.util.TypedValue;
import android.view.View;
import android.widget.TextView;
public class SizeListener implements View.OnClickListener{
    private TextView tv;
    public SizeListener(TextView tv){
        this.tv=tv;
    }
    public void onClick(View v){
        float f=tv.getTextSize();
        switch (v.getId()){
            case R.id.bigger:
                f=f+4;
                break;
            case R.id.smaller:
                f=f-4;
                break;
            default:
                break;}
        if(f<=8){
            f=8;}
        tv.setTextSize(TypedValue.COMPLEX_UNIT_PX,f);
    }
}
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activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<TableLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <TextView
        android:id="@+id/testTest"
        android:gravity="center"
        android:text="@string/test_text"
        android:padding="10dp"
        android:textSize="20sp"/>
    <TableRow
        android:layout_marginLeft="10dp">
        <TextView android:text="@string/size"/>
        <Button
            android:id="@+id/bigger"
            android:text="@string/bigger"/>
        <Button
            android:id="@+id/smaller"
            android:text="@string/smaller"/>
    </TableRow>
    <TableRow
        android:layout_marginLeft="10dp">
        <TextView android:text="@string/color"/>
        <Button
            android:id="@+id/red"
            android:text="@string/red"/>
        <Button
            android:id="@+id/green"
            android:text="@string/green"/>
        <Button
            android:id="@+id/blue"
            android:text="@string/blue"/>
    </TableRow>
    <TableRow
        android:layout_marginLeft="10dp">
        <TextView android:text="@string/style"/>
        <Button
            android:id="@+id/bold"
            android:text="@string/bold"/>
        <Button
            android:id="@+id/italic"
            android:text="@string/italic"/>
        <Button
            android:id="@+id/moren"
            android:text="@string/moren"/>
    </TableRow>
  </TableLayout>
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strings.xml:

<resources>
    <string name="app_name">文本编辑器</string>
    <string name="hello_world">Hello world</string>
    <string name="menu_settings">Settings</string>
    <string name="color">颜色</string>
    <string name="red">红色</string>
    <string name="green">绿色</string>
    <string name="blue">蓝色</string>
    <string name="size">大小</string>
    <string name="bigger">增大</string>
    <string name="smaller">变小</string>
    <string name="style">样式</string>
    <string name="bold">加粗</string>
    <string name="italic">倾斜</string>
    <string name="content">内容</string>
    <string name="test_text">我是计算机应用班邓家帅</string>
    <string name="moren">默认</string>
</resources>
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运行结果：