Java tutorial
/* * Copyright (C) 2007 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.preference; import android.annotation.UnsupportedAppUsage; import android.content.Context; import android.content.SharedPreferences; import android.content.res.TypedArray; import android.os.Parcel; import android.os.Parcelable; import android.text.TextUtils; import android.util.AttributeSet; import android.view.View; import android.view.ViewGroup; import android.view.ViewParent; import android.widget.EditText; /** * A {@link Preference} that allows for string * input. * <p> * It is a subclass of {@link DialogPreference} and shows the {@link EditText} * in a dialog. This {@link EditText} can be modified either programmatically * via {@link #getEditText()}, or through XML by setting any EditText * attributes on the EditTextPreference. * <p> * This preference will store a string into the SharedPreferences. * <p> * See {@link android.R.styleable#EditText EditText Attributes}. */ public class EditTextPreference extends DialogPreference { /** * The edit text shown in the dialog. */ @UnsupportedAppUsage private EditText mEditText; private String mText; private boolean mTextSet; public EditTextPreference(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) { super(context, attrs, defStyleAttr, defStyleRes); mEditText = new EditText(context, attrs); // Give it an ID so it can be saved/restored mEditText.setId(com.android.internal.R.id.edit); /* * The preference framework and view framework both have an 'enabled' * attribute. Most likely, the 'enabled' specified in this XML is for * the preference framework, but it was also given to the view framework. * We reset the enabled state. */ mEditText.setEnabled(true); } public EditTextPreference(Context context, AttributeSet attrs, int defStyleAttr) { this(context, attrs, defStyleAttr, 0); } public EditTextPreference(Context context, AttributeSet attrs) { this(context, attrs, com.android.internal.R.attr.editTextPreferenceStyle); } public EditTextPreference(Context context) { this(context, null); } /** * Saves the text to the {@link SharedPreferences}. * * @param text The text to save */ public void setText(String text) { // Always persist/notify the first time. final boolean changed = !TextUtils.equals(mText, text); if (changed || !mTextSet) { mText = text; mTextSet = true; persistString(text); if (changed) { notifyDependencyChange(shouldDisableDependents()); notifyChanged(); } } } /** * Gets the text from the {@link SharedPreferences}. * * @return The current preference value. */ public String getText() { return mText; } @Override protected void onBindDialogView(View view) { super.onBindDialogView(view); EditText editText = mEditText; editText.setText(getText()); ViewParent oldParent = editText.getParent(); if (oldParent != view) { if (oldParent != null) { ((ViewGroup) oldParent).removeView(editText); } onAddEditTextToDialogView(view, editText); } } /** * Adds the EditText widget of this preference to the dialog's view. * * @param dialogView The dialog view. */ protected void onAddEditTextToDialogView(View dialogView, EditText editText) { ViewGroup container = (ViewGroup) dialogView.findViewById(com.android.internal.R.id.edittext_container); if (container != null) { container.addView(editText, ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT); } } @Override protected void onDialogClosed(boolean positiveResult) { super.onDialogClosed(positiveResult); if (positiveResult) { String value = mEditText.getText().toString(); if (callChangeListener(value)) { setText(value); } } } @Override protected Object onGetDefaultValue(TypedArray a, int index) { return a.getString(index); } @Override protected void onSetInitialValue(boolean restoreValue, Object defaultValue) { setText(restoreValue ? getPersistedString(mText) : (String) defaultValue); } @Override public boolean shouldDisableDependents() { return TextUtils.isEmpty(mText) || super.shouldDisableDependents(); } /** * Returns the {@link EditText} widget that will be shown in the dialog. * * @return The {@link EditText} widget that will be shown in the dialog. */ public EditText getEditText() { return mEditText; } /** @hide */ @Override protected boolean needInputMethod() { // We want the input method to show, if possible, when dialog is displayed return true; } @Override protected Parcelable onSaveInstanceState() { final Parcelable superState = super.onSaveInstanceState(); if (isPersistent()) { // No need to save instance state since it's persistent return superState; } final SavedState myState = new SavedState(superState); myState.text = getText(); return myState; } @Override protected void onRestoreInstanceState(Parcelable state) { if (state == null || !state.getClass().equals(SavedState.class)) { // Didn't save state for us in onSaveInstanceState super.onRestoreInstanceState(state); return; } SavedState myState = (SavedState) state; super.onRestoreInstanceState(myState.getSuperState()); setText(myState.text); } private static class SavedState extends BaseSavedState { String text; public SavedState(Parcel source) { super(source); text = source.readString(); } @Override public void writeToParcel(Parcel dest, int flags) { super.writeToParcel(dest, flags); dest.writeString(text); } public SavedState(Parcelable superState) { super(superState); } public static final Parcelable.Creator<SavedState> CREATOR = new Parcelable.Creator<SavedState>() { public SavedState createFromParcel(Parcel in) { return new SavedState(in); } public SavedState[] newArray(int size) { return new SavedState[size]; } }; } }