Android的输入框中加入清除按钮

package com.ming.doustec.clearableedittextdemo;

import android.content.Context;
import android.graphics.drawable.Drawable;
import android.support.v4.content.ContextCompat;
import android.support.v4.graphics.drawable.DrawableCompat;
import android.support.v7.widget.AppCompatEditText;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;

/**
* Created by ds03 on 2015/9/11.
*/
public class ClearableEditText extends AppCompatEditText implements View.OnTouchListener, View.OnFocusChangeListener, TextWatcher {

private Drawable mClearTextIcon;
private OnFocusChangeListener mOnFocusChangeListener;
private OnTouchListener mOnTouchListener;

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

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

public ClearableEditText(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init(context);
}

private void init(Context context){
//封装drawable对象
Drawable drawable = ContextCompat.getDrawable(context,R.drawable.abc_ic_clear_mtrl_alpha);
Drawable wrappedDrawable = DrawableCompat.wrap(drawable);
//简单着色
DrawableCompat.setTint(wrappedDrawable, getCurrentHintTextColor());

mClearTextIcon = wrappedDrawable;
//设置宽高
mClearTextIcon.setBounds(0, 0, mClearTextIcon.getIntrinsicHeight(), mClearTextIcon.getIntrinsicWidth());

setClearIconVisible(false);

super.setOnTouchListener(this);
super.setOnFocusChangeListener(this);
addTextChangedListener(this);
}

private void setClearIconVisible(final boolean visible) {
mClearTextIcon.setVisible(visible, false);
final Drawable[] compoundDrawables = getCompoundDrawables();
//在edittext右侧设置图标
setCompoundDrawables(
compoundDrawables[0],
compoundDrawables[1],
visible ? mClearTextIcon : null,
compoundDrawables[3]);
}

@Override
public void onFocusChange(View v, boolean hasFocus) {
if (hasFocus) {
setClearIconVisible(getText().length() > 0);
} else {
setClearIconVisible(false);
}
if (mOnFocusChangeListener != null) {
mOnFocusChangeListener.onFocusChange(v, hasFocus);
}
}

@Override
public boolean onTouch(View v, MotionEvent event) {
final int x = (int) event.getX();
if (mClearTextIcon.isVisible() && x > getWidth() - getPaddingRight() - mClearTextIcon.getIntrinsicWidth()) {
if (event.getAction() == MotionEvent.ACTION_UP) {
setError(null);
setText("");
}
return true;
}
return mOnTouchListener != null && mOnTouchListener.onTouch(v, event);
}

@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {

}

@Override
public void afterTextChanged(Editable s) {

}
@Override
public final void onTextChanged(final CharSequence s, final int start, final int before, final int count) {
if (isFocused()) {
setClearIconVisible(s.length() > 0);
}
}

@Override
public void setOnFocusChangeListener(final OnFocusChangeListener onFocusChangeListener) {
mOnFocusChangeListener = onFocusChangeListener;
}

@Override
public void setOnTouchListener(final OnTouchListener onTouchListener) {
mOnTouchListener = onTouchListener;
}
}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center_horizontal"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".LoginActivity">

<!-- Login progress -->
<ProgressBar
android:id="@+id/login_progress"
style="?android:attr/progressBarStyleLarge"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="8dp"
android:visibility="gone" />

<ScrollView
android:id="@+id/login_form"
android:layout_width="match_parent"
android:layout_height="match_parent">

<LinearLayout
android:id="@+id/email_login_form"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">

<android.support.design.widget.TextInputLayout
android:id="@+id/email_text_input_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content">

<com.ming.doustec.clearableedittextdemo.ClearableEditText
android:id="@+id/email"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="@string/prompt_email"
android:imeOptions="flagNoExtractUi"
android:singleLine="true" />
</android.support.design.widget.TextInputLayout>

<android.support.design.widget.TextInputLayout
android:id="@+id/password_text_input_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content">

<com.ming.doustec.clearableedittextdemo.ClearableEditText
android:id="@+id/password"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fontFamily="sans-serif"
android:hint="@string/prompt_password"
android:imeActionId="@+id/login"
android:imeActionLabel="@string/action_sign_in_short"
android:imeOptions="flagNoFullscreen|actionUnspecified"
android:inputType="textPassword"
android:singleLine="true" />
</android.support.design.widget.TextInputLayout>

<Button
android:id="@+id/email_sign_in_button"
style="?android:textAppearanceSmallInverse"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="16dp"
android:text="@string/action_sign_in"
android:textStyle="bold"
/>

</LinearLayout>
</ScrollView>

</LinearLayout>

package com.ming.doustec.clearableedittextdemo;

import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.app.Activity;
import android.content.res.Configuration;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.design.widget.TextInputLayout;
import android.support.v7.app.AppCompatActivity;
import android.text.TextUtils;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.inputmethod.EditorInfo;
import android.widget.Button;
import android.widget.TextView;

public class LoginActivity extends AppCompatActivity {

/**
* A dummy authentication store containing known user names and passwords.
* TODO: remove after connecting to a real authentication system.
*/
private static final String[] DUMMY_CREDENTIALS = new String[]{
"foo@example.com:hello", "bar@example.com:world"
};
/**
* Keep track of the login task to ensure we can cancel it if requested.
*/
private UserLoginTask mAuthTask = null;

// UI references.
private TextInputLayout mEmailView;
private TextInputLayout mPasswordView;
private View mProgressView;
private View mLoginFormView;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
setTitle(R.string.action_sign_in_short);

// Set up the login form.
mEmailView = (TextInputLayout) findViewById(R.id.email_text_input_layout);

mPasswordView = (TextInputLayout) findViewById(R.id.password_text_input_layout);

mPasswordView.getEditText().setOnEditorActionListener(new TextView.OnEditorActionListener() {
@Override
public boolean onEditorAction(TextView textView, int id, KeyEvent keyEvent) {
if (id == R.id.login || id == EditorInfo.IME_NULL) {
attemptLogin();
return true;
}
return false;
}
});

final Button emailSignInButton = (Button) findViewById(R.id.email_sign_in_button);
emailSignInButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
attemptLogin();
}
});

mLoginFormView = findViewById(R.id.login_form);
mProgressView = findViewById(R.id.login_progress);
}

@Override
protected void onResume() {
super.onResume();
if (!getResources().getBoolean(R.bool.is_tablet) && getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) {
getSupportActionBar().hide();
} else {
getSupportActionBar().show();
}
}

/**
* Attempts to sign in or register the account specified by the login form.
* If there are form errors (invalid email, missing fields, etc.), the
* errors are presented and no actual login attempt is made.
*/
public void attemptLogin() {
if (mAuthTask != null) {
return;
}

// Reset errors.
mEmailView.setErrorEnabled(false);
mPasswordView.setErrorEnabled(false);

// Store values at the time of the login attempt.
String email = mEmailView.getEditText().getText().toString();
String password = mPasswordView.getEditText().getText().toString();

boolean cancel = false;
View focusView = null;

// Check for a valid password, if the user entered one.
if (!TextUtils.isEmpty(password) && !isPasswordValid(password)) {
mPasswordView.setError(getString(R.string.error_invalid_password));
focusView = mPasswordView;
cancel = true;
}

// Check for a valid email address.
if (TextUtils.isEmpty(email)) {
mEmailView.setError(getString(R.string.error_field_required));
focusView = mEmailView;
cancel = true;
} else if (!isEmailValid(email)) {
mEmailView.setError(getString(R.string.error_invalid_email));
focusView = mEmailView;
cancel = true;
}

if (cancel) {
// There was an error; don't attempt login and focus the first
// form field with an error.
focusView.requestFocus();
} else {
// Show a progress spinner, and kick off a background task to
// perform the user login attempt.
showProgress(true);
mAuthTask = new UserLoginTask(email, password);
mAuthTask.execute((Void) null);
}
}

private boolean isEmailValid(String email) {
//TODO: Replace this with your own logic
return email.contains("@");
}

private boolean isPasswordValid(String password) {
//TODO: Replace this with your own logic
return password.length() > 4;
}

/**
* Shows the progress UI and hides the login form.
*/
public void showProgress(final boolean show) {
int shortAnimTime = getResources().getInteger(android.R.integer.config_shortAnimTime);

mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
mLoginFormView.animate().setDuration(shortAnimTime).alpha(
show ? 0 : 1).setListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
}
});

mProgressView.setVisibility(show ? View.VISIBLE : View.GONE);
mProgressView.animate().setDuration(shortAnimTime).alpha(
show ? 1 : 0).setListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
mProgressView.setVisibility(show ? View.VISIBLE : View.GONE);
}
});
}

/**
* Represents an asynchronous login/registration task used to authenticate
* the user.
*/
public class UserLoginTask extends AsyncTask<Void, Void, Boolean> {

private final String mEmail;
private final String mPassword;

UserLoginTask(String email, String password) {
mEmail = email;
mPassword = password;
}

@Override
protected Boolean doInBackground(Void... params) {
// TODO: attempt authentication against a network service.

try {
// Simulate network access.
Thread.sleep(2000);
} catch (InterruptedException e) {
return false;
}

for (String credential : DUMMY_CREDENTIALS) {
String[] pieces = credential.split(":");
if (pieces[0].equals(mEmail)) {
// Account exists, return true if the password matches.
return pieces[1].equals(mPassword);
}
}

// TODO: register the new account here.
return true;
}

@Override
protected void onPostExecute(final Boolean success) {
mAuthTask = null;
showProgress(false);

if (success) {
finish();
} else {
mPasswordView.setError(getString(R.string.error_incorrect_password));
mPasswordView.requestFocus();
}
}

@Override
protected void onCancelled() {
mAuthTask = null;
showProgress(false);
}
}
}