Java tutorial
/* * Copyright 2016 Hippo Seven * * 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 com.hippo.preference; import android.app.Dialog; import android.content.Context; import android.content.DialogInterface; import android.content.SharedPreferences; import android.content.res.TypedArray; import android.graphics.drawable.Drawable; import android.os.Bundle; import android.os.Parcel; import android.os.Parcelable; import android.preference.Preference; import android.preference.PreferenceManager; import android.support.annotation.DrawableRes; import android.support.annotation.StringRes; import android.support.v4.content.ContextCompat; import android.support.v7.app.AlertDialog; import android.util.AttributeSet; import android.view.LayoutInflater; import android.view.View; import android.view.Window; import android.view.WindowManager; import com.hippo.ehviewer.R; /** * A base class for {@link Preference} objects that are * dialog-based. These preferences will, when clicked, open a dialog showing the * actual preference controls. */ public abstract class DialogPreference extends Preference implements DialogInterface.OnClickListener, DialogInterface.OnDismissListener, PreferenceManager.OnActivityDestroyListener { private AlertDialog.Builder mBuilder; private CharSequence mDialogTitle; private Drawable mDialogIcon; private CharSequence mPositiveButtonText; private CharSequence mNegativeButtonText; private int mDialogLayoutResId; /** The dialog, if it is showing. */ private AlertDialog mDialog; /** Which button was clicked. */ private int mWhichButtonClicked; public DialogPreference(Context context) { super(context); init(context, null, 0, 0); } public DialogPreference(Context context, AttributeSet attrs) { super(context, attrs); init(context, attrs, 0, 0); } public DialogPreference(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); init(context, attrs, defStyleAttr, 0); } private void init(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) { final TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.DialogPreference, defStyleAttr, defStyleRes); mDialogTitle = a.getString(R.styleable.DialogPreference_dialogTitle); if (mDialogTitle == null) { // Fallback on the regular title of the preference // (the one that is seen in the list) mDialogTitle = getTitle(); } mDialogIcon = a.getDrawable(R.styleable.DialogPreference_dialogIcon); mPositiveButtonText = a.getString(R.styleable.DialogPreference_positiveButtonText); mNegativeButtonText = a.getString(R.styleable.DialogPreference_negativeButtonText); mDialogLayoutResId = a.getResourceId(R.styleable.DialogPreference_dialogLayout, mDialogLayoutResId); a.recycle(); } /** * Sets the title of the dialog. This will be shown on subsequent dialogs. * * @param dialogTitle The title. */ public void setDialogTitle(CharSequence dialogTitle) { mDialogTitle = dialogTitle; } /** * @see #setDialogTitle(CharSequence) * @param dialogTitleResId The dialog title as a resource. */ public void setDialogTitle(int dialogTitleResId) { setDialogTitle(getContext().getString(dialogTitleResId)); } /** * Returns the title to be shown on subsequent dialogs. * @return The title. */ public CharSequence getDialogTitle() { return mDialogTitle; } /** * Sets the icon of the dialog. This will be shown on subsequent dialogs. * * @param dialogIcon The icon, as a {@link Drawable}. */ public void setDialogIcon(Drawable dialogIcon) { mDialogIcon = dialogIcon; } /** * Sets the icon (resource ID) of the dialog. This will be shown on * subsequent dialogs. * * @param dialogIconRes The icon, as a resource ID. */ public void setDialogIcon(@DrawableRes int dialogIconRes) { mDialogIcon = ContextCompat.getDrawable(getContext(), dialogIconRes); } /** * Returns the icon to be shown on subsequent dialogs. * @return The icon, as a {@link Drawable}. */ public Drawable getDialogIcon() { return mDialogIcon; } /** * Sets the text of the positive button of the dialog. This will be shown on * subsequent dialogs. * * @param positiveButtonText The text of the positive button. */ public void setPositiveButtonText(CharSequence positiveButtonText) { mPositiveButtonText = positiveButtonText; } /** * @see #setPositiveButtonText(CharSequence) * @param positiveButtonTextResId The positive button text as a resource. */ public void setPositiveButtonText(@StringRes int positiveButtonTextResId) { setPositiveButtonText(getContext().getString(positiveButtonTextResId)); } /** * Returns the text of the positive button to be shown on subsequent * dialogs. * * @return The text of the positive button. */ public CharSequence getPositiveButtonText() { return mPositiveButtonText; } /** * Sets the text of the negative button of the dialog. This will be shown on * subsequent dialogs. * * @param negativeButtonText The text of the negative button. */ public void setNegativeButtonText(CharSequence negativeButtonText) { mNegativeButtonText = negativeButtonText; } /** * @see #setNegativeButtonText(CharSequence) * @param negativeButtonTextResId The negative button text as a resource. */ public void setNegativeButtonText(@StringRes int negativeButtonTextResId) { setNegativeButtonText(getContext().getString(negativeButtonTextResId)); } /** * Returns the text of the negative button to be shown on subsequent * dialogs. * * @return The text of the negative button. */ public CharSequence getNegativeButtonText() { return mNegativeButtonText; } /** * Sets the layout resource that is inflated as the {@link View} to be shown * as the content View of subsequent dialogs. * * @param dialogLayoutResId The layout resource ID to be inflated. */ public void setDialogLayoutResource(int dialogLayoutResId) { mDialogLayoutResId = dialogLayoutResId; } /** * Returns the layout resource that is used as the content View for * subsequent dialogs. * * @return The layout resource. */ public int getDialogLayoutResource() { return mDialogLayoutResId; } /** * Prepares the dialog builder to be shown when the preference is clicked. * Use this to set custom properties on the dialog. * <p> * Do not {@link AlertDialog.Builder#create()} or * {@link AlertDialog.Builder#show()}. */ protected void onPrepareDialogBuilder(AlertDialog.Builder builder) { } @Override protected void onClick() { if (mDialog != null && mDialog.isShowing()) return; showDialog(null); } /** * Shows the dialog associated with this Preference. This is normally initiated * automatically on clicking on the preference. Call this method if you need to * show the dialog on some other event. * * @param state Optional instance state to restore on the dialog */ protected void showDialog(Bundle state) { Context context = getContext(); mWhichButtonClicked = DialogInterface.BUTTON_NEGATIVE; mBuilder = new AlertDialog.Builder(context).setTitle(mDialogTitle).setIcon(mDialogIcon) .setPositiveButton(mPositiveButtonText, this).setNegativeButton(mNegativeButtonText, this); View contentView = onCreateDialogView(); if (contentView != null) { onBindDialogView(contentView); mBuilder.setView(contentView); } onPrepareDialogBuilder(mBuilder); PreferenceUtils.registerOnActivityDestroyListener(this, this); // Create the dialog final AlertDialog dialog = mDialog = mBuilder.create(); if (state != null) { dialog.onRestoreInstanceState(state); } if (needInputMethod()) { requestInputMethod(dialog); } dialog.setOnDismissListener(this); dialog.show(); onDialogCreated(dialog); } /** * Returns whether the preference needs to display a soft input method when the dialog * is displayed. Default is false. Subclasses should override this method if they need * the soft input method brought up automatically. */ protected boolean needInputMethod() { return false; } /** * Sets the required flags on the dialog window to enable input method window to show up. */ private void requestInputMethod(Dialog dialog) { Window window = dialog.getWindow(); window.setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_VISIBLE); } /** * Creates the content view for the dialog (if a custom content view is * required). By default, it inflates the dialog layout resource if it is * set. * * @return The content View for the dialog. * @see #setLayoutResource(int) */ protected View onCreateDialogView() { if (mDialogLayoutResId == 0) { return null; } LayoutInflater inflater = LayoutInflater.from(mBuilder.getContext()); return inflater.inflate(mDialogLayoutResId, null); } /** * Binds views in the content View of the dialog to data. * * @param view The content View of the dialog, if it is custom. */ protected void onBindDialogView(View view) { } protected void onDialogCreated(AlertDialog dialog) { } @Override public void onClick(DialogInterface dialog, int which) { mWhichButtonClicked = which; } @Override public void onDismiss(DialogInterface dialog) { PreferenceUtils.unregisterOnActivityDestroyListener(this, this); mDialog = null; onDialogClosed(mWhichButtonClicked == DialogInterface.BUTTON_POSITIVE); } /** * Called when the dialog is dismissed and should be used to save data to * the {@link SharedPreferences}. * * @param positiveResult Whether the positive button was clicked (true), or * the negative button was clicked or the dialog was canceled (false). */ protected void onDialogClosed(boolean positiveResult) { } /** * Gets the dialog that is shown by this preference. * * @return The dialog, or null if a dialog is not being shown. */ public Dialog getDialog() { return mDialog; } @Override public void onActivityDestroy() { if (mDialog == null || !mDialog.isShowing()) { return; } mDialog.dismiss(); } @Override protected Parcelable onSaveInstanceState() { final Parcelable superState = super.onSaveInstanceState(); if (mDialog == null || !mDialog.isShowing()) { return superState; } final SavedState myState = new SavedState(superState); myState.isDialogShowing = true; myState.dialogBundle = mDialog.onSaveInstanceState(); 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()); if (myState.isDialogShowing) { showDialog(myState.dialogBundle); } } private static class SavedState extends BaseSavedState { boolean isDialogShowing; Bundle dialogBundle; public SavedState(Parcel source) { super(source); isDialogShowing = source.readInt() == 1; dialogBundle = source.readBundle(DialogPreference.class.getClassLoader()); } @Override public void writeToParcel(Parcel dest, int flags) { super.writeToParcel(dest, flags); dest.writeInt(isDialogShowing ? 1 : 0); dest.writeBundle(dialogBundle); } public SavedState(Parcelable superState) { super(superState); } public static final Parcelable.Creator<SavedState> CREATOR = new Parcelable.Creator<SavedState>() { @Override public SavedState createFromParcel(Parcel in) { return new SavedState(in); } @Override public SavedState[] newArray(int size) { return new SavedState[size]; } }; } }