core/java/android/text/method/TransformationMethod.java

/*
 * Copyright (C) 2006 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.text.method;

import android.graphics.Rect;
import android.view.View;

/**
 * TextView uses TransformationMethods to do things like replacing the
 * characters of passwords with dots, or keeping the newline characters
 * from causing line breaks in single-line text fields.
 */
public interface TransformationMethod
{
    /**
     * Returns a CharSequence that is a transformation of the source text --
     * for example, replacing each character with a dot in a password field.
     * Beware that the returned text must be exactly the same length as
     * the source text, and that if the source text is Editable, the returned
     * text must mirror it dynamically instead of doing a one-time copy.
     */
    public CharSequence getTransformation(CharSequence source, View view);

    /**
     * This method is called when the TextView that uses this
     * TransformationMethod gains or loses focus.
     */
    public void onFocusChanged(View view, CharSequence sourceText,
                               boolean focused, int direction,
                               Rect previouslyFocusedRect);
}