InputFilter & DynamicLayout

.gitignore

gen/
bin/
.classpath
.project

README

Sample for InputFilter & DynamicLayout

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.kayac.test.edittext"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk android:minSdkVersion="4" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:label="@string/app_name"
            android:name=".InputFilterTestActivity" >
            <intent-filter >
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

ic_launcher.png

ic_launcher.png

ic_launcher.png

InputFilterTestActivity.java

package com.kayac.test.edittext;

import android.app.Activity;
import android.os.Bundle;
import android.widget.EditText;

public class InputFilterTestActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        EditText editText = (EditText) findViewById(R.id.editText);
        
        // test emoji
        Bundle bundle = editText.getInputExtras(true);
        if (bundle != null) {
            bundle.putBoolean("allowEmoji", true);
        }
    }
}

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <com.kayac.test.edittext.MaximumLineBoundedEditText
        android:id="@+id/editText"
        android:layout_width="300dp"
        android:layout_height="200dp"
        android:padding="20dp"
        android:singleLine="false"
        android:gravity="center"
        android:layout_gravity="center"
        android:text="@string/hello" />
</LinearLayout>

MaximumLineBoundedEditText.java

package com.kayac.test.edittext;

import android.content.Context;
import android.text.DynamicLayout;
import android.text.InputFilter;
import android.text.Spanned;
import android.text.Layout.Alignment;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.widget.EditText;
import android.widget.Toast;

public class MaximumLineBoundedEditText extends EditText {
    private static final int MAX_LINES_DEFAULT = 3;
    private int mMaxLines = MAX_LINES_DEFAULT;
    // for debugging purpose.
    private long mToastTimestamp = -1;
    
    public MaximumLineBoundedEditText(Context context, AttributeSet attrs) {
        super(context, attrs);
        
        setFilters(mInputFilters);
    }
    
    public void setMaxLines(int maxLines) {
        mMaxLines = maxLines;
    }
    
    public int getMaxLines() {
        return mMaxLines;
    }
    
    private InputFilter[] mInputFilters = new InputFilter[] {
        new InputFilter() {
            @Override
            public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {
                // first, calculate the next CharSequence, which would be displayed.
                CharSequence base = TextUtils.concat(
                    dest.subSequence(0, dstart),
                    source.subSequence(start, end),
                    dest.subSequence(dend, dest.length()));
                
                // Layout class is used internally in TextView to calculate
                // the actual size and to draw the text
                DynamicLayout layout = new DynamicLayout(
                    base, getPaint(),
                    getWidth() - getPaddingRight() - getPaddingLeft(), // desired width with paddings
                    Alignment.ALIGN_CENTER, 1.0f, 0.0f, true);
                
                // calculate the line count which is needed to display 
                // the new CharSequence
                int lines =  layout.getLineCount();
                
                if (lines > mMaxLines && // if the new line count exceeds the maximum and
                        (end - start) - (dend- dstart) > 0) { // the replacement increases the length of the CharSequence
                    long t = System.currentTimeMillis();
                    if (t - mToastTimestamp > 1000) {
                        mToastTimestamp = t;
                        Toast.makeText(getContext(), "You cannot input text which is longer than " +mMaxLines+" lines!", Toast.LENGTH_SHORT)
                            .show();
                    }
                    return ""; // then decline the input
                }

                // otherwise, keep original
                return null;
            }
        }
    };
}

proguard.cfg

-optimizationpasses 5
-dontusemixedcaseclassnames
-dontskipnonpubliclibraryclasses
-dontpreverify
-verbose
-optimizations !code/simplification/arithmetic,!field/*,!class/merging/*

-keep public class * extends android.app.Activity
-keep public class * extends android.app.Application
-keep public class * extends android.app.Service
-keep public class * extends android.content.BroadcastReceiver
-keep public class * extends android.content.ContentProvider
-keep public class * extends android.app.backup.BackupAgentHelper
-keep public class * extends android.preference.Preference
-keep public class com.android.vending.licensing.ILicensingService

-keepclasseswithmembernames class * {
    native <methods>;
}

-keepclasseswithmembers class * {
    public <init>(android.content.Context, android.util.AttributeSet);
}

-keepclasseswithmembers class * {
    public <init>(android.content.Context, android.util.AttributeSet, int);
}

-keepclassmembers class * extends android.app.Activity {
   public void *(android.view.View);
}

-keepclassmembers enum * {
    public static **[] values();
    public static ** valueOf(java.lang.String);
}

-keep class * implements android.os.Parcelable {
  public static final android.os.Parcelable$Creator *;
}

project.properties

# This file is automatically generated by Android Tools.
# Do not modify this file -- YOUR CHANGES WILL BE ERASED!
#
# This file must be checked in Version Control Systems.
#
# To customize properties used by the Ant build system use,
# "ant.properties", and override values to adapt the script to your
# project structure.

# Project target.
target=android-4

strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="hello">Hello World, InputFilterTestActivity!</string>
    <string name="app_name">InputFilterTest</string>

</resources>