Java tutorial
/* * Copyright (C) 2011 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.support.v4.app.support; import java.lang.reflect.Field; import android.app.Activity; import android.content.Context; import android.content.DialogInterface; import android.os.Bundle; import android.support.v4.app.Dialog; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentManager; import android.support.v4.app.FragmentTransaction; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.view.Window; import android.view.WindowManager; /** * Static library support version of the framework's {@link android.app.DialogFragment}. * Used to write apps that run on platforms prior to Android 3.0. When running * on Android 3.0 or above, this implementation is still used; it does not try * to switch to the framework's implementation. See the framework SDK * documentation for a class overview. */ public class DialogFragment extends Fragment implements DialogInterface.OnCancelListener, DialogInterface.OnDismissListener { /** * Style for {@link #setStyle(int, int)}: a basic, * normal dialog. */ public static final int STYLE_NORMAL = 0; /** * Style for {@link #setStyle(int, int)}: don't include * a title area. */ public static final int STYLE_NO_TITLE = 1; /** * Style for {@link #setStyle(int, int)}: don't draw * any frame at all; the view hierarchy returned by {@link #onCreateView} is entirely * responsible for drawing the dialog. */ public static final int STYLE_NO_FRAME = 2; /** * Style for {@link #setStyle(int, int)}: like {@link #STYLE_NO_FRAME}, but also disables all * input to the dialog. * The user can not touch it, and its window will not receive input focus. */ public static final int STYLE_NO_INPUT = 3; private static final String SAVED_DIALOG_STATE_TAG = "android:savedDialogState"; private static final String SAVED_STYLE = "android:style"; private static final String SAVED_THEME = "android:theme"; private static final String SAVED_CANCELABLE = "android:cancelable"; private static final String SAVED_SHOWS_DIALOG = "android:showsDialog"; private static final String SAVED_BACK_STACK_ID = "android:backStackId"; int mStyle = STYLE_NORMAL; int mTheme = 0; boolean mCancelable = true; boolean mShowsDialog = true; int mBackStackId = -1; Dialog mDialog; boolean mViewDestroyed; boolean mDismissed; boolean mShownByMe; public DialogFragment() { } /** * Call to customize the basic appearance and behavior of the * fragment's dialog. This can be used for some common dialog behaviors, * taking care of selecting flags, theme, and other options for you. The * same effect can be achieve by manually setting Dialog and Window * attributes yourself. Calling this after the fragment's Dialog is * created will have no effect. * * @param style * Selects a standard style: may be {@link #STYLE_NORMAL}, {@link #STYLE_NO_TITLE}, * {@link #STYLE_NO_FRAME}, or {@link #STYLE_NO_INPUT}. * @param theme * Optional custom theme. If 0, an appropriate theme (based * on the style) will be selected for you. */ public void setStyle(int style, int theme) { mStyle = style; if (mStyle == STYLE_NO_FRAME || mStyle == STYLE_NO_INPUT) { mTheme = android.R.style.Theme_Panel; } if (theme != 0) { mTheme = theme; } } /** * Display the dialog, adding the fragment to the given FragmentManager. This * is a convenience for explicitly creating a transaction, adding the * fragment to it with the given tag, and committing it. This does <em>not</em> add the * transaction to the back stack. When the fragment * is dismissed, a new transaction will be executed to remove it from * the activity. * * @param manager * The FragmentManager this fragment will be added to. * @param tag * The tag for this fragment, as per * {@link FragmentTransaction#add(Fragment, String) FragmentTransaction.add}. */ public void show(FragmentManager manager, String tag) { mDismissed = false; mShownByMe = true; FragmentTransaction ft = manager.beginTransaction(); ft.add(this, tag); ft.commit(); } /** * Display the dialog, adding the fragment using an existing transaction * and then committing the transaction. * * @param transaction * An existing transaction in which to add the fragment. * @param tag * The tag for this fragment, as per * {@link FragmentTransaction#add(Fragment, String) FragmentTransaction.add}. * @return Returns the identifier of the committed transaction, as per * {@link FragmentTransaction#commit() FragmentTransaction.commit()}. */ public int show(FragmentTransaction transaction, String tag) { mDismissed = false; mShownByMe = true; transaction.add(this, tag); mViewDestroyed = false; mBackStackId = transaction.commit(); return mBackStackId; } /** * Dismiss the fragment and its dialog. If the fragment was added to the * back stack, all back stack state up to and including this entry will * be popped. Otherwise, a new transaction will be committed to remove * the fragment. */ public void dismiss() { dismissInternal(false); } /** * Version of {@link #dismiss()} that uses {@link FragmentTransaction#commitAllowingStateLoss() * FragmentTransaction.commitAllowingStateLoss()}. See linked * documentation for further details. */ public void dismissAllowingStateLoss() { dismissInternal(true); } void dismissInternal(boolean allowStateLoss) { if (mDismissed) { return; } mDismissed = true; mShownByMe = false; if (mDialog != null) { mDialog.dismiss(); mDialog = null; } mViewDestroyed = true; if (mBackStackId >= 0) { getFragmentManager().popBackStack(mBackStackId, FragmentManager.POP_BACK_STACK_INCLUSIVE); mBackStackId = -1; } else { FragmentTransaction ft = getFragmentManager().beginTransaction(); ft.remove(this); if (allowStateLoss) { ft.commitAllowingStateLoss(); } else { ft.commit(); } } } public Dialog getDialog() { return mDialog; } public int getTheme() { return mTheme; } /** * Control whether the shown Dialog is cancelable. Use this instead of * directly calling {@link Dialog#setCancelable(boolean) * Dialog.setCancelable(boolean)}, because DialogFragment needs to change * its behavior based on this. * * @param cancelable * If true, the dialog is cancelable. The default * is true. */ public void setCancelable(boolean cancelable) { mCancelable = cancelable; if (mDialog != null) mDialog.setCancelable(cancelable); } /** * Return the current value of {@link #setCancelable(boolean)}. */ public boolean isCancelable() { return mCancelable; } /** * Controls whether this fragment should be shown in a dialog. If not * set, no Dialog will be created in {@link #onActivityCreated(Bundle)}, * and the fragment's view hierarchy will thus not be added to it. This * allows you to instead use it as a normal fragment (embedded inside of * its activity). * <p> * This is normally set for you based on whether the fragment is associated with a container * view ID passed to {@link FragmentTransaction#add(int, Fragment) FragmentTransaction.add(int, * Fragment)}. If the fragment was added with a container, setShowsDialog will be initialized to * false; otherwise, it will be true. * * @param showsDialog * If true, the fragment will be displayed in a Dialog. * If false, no Dialog will be created and the fragment's view hierarchly * left undisturbed. */ public void setShowsDialog(boolean showsDialog) { mShowsDialog = showsDialog; } /** * Return the current value of {@link #setShowsDialog(boolean)}. */ public boolean getShowsDialog() { return mShowsDialog; } @Override public void onAttach(Activity activity) { super.onAttach(activity); if (!mShownByMe) { // If not explicitly shown through our API, take this as an // indication that the dialog is no longer dismissed. mDismissed = false; } } @Override public void onDetach() { super.onDetach(); if (!mShownByMe && !mDismissed) { // The fragment was not shown by a direct call here, it is not // dismissed, and now it is being detached... well, okay, thou // art now dismissed. Have fun. mDismissed = true; } } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); // mShowsDialog = mContainerId == 0; int mContainerId = 0; Field f; try { f = getClass().getSuperclass().getDeclaredField("mContainerId"); f.setAccessible(true); mContainerId = (Integer) f.get(this); } catch (NoSuchFieldException e) { } catch (IllegalAccessException e) { } catch (IllegalArgumentException e) { } mShowsDialog = mContainerId == 0; if (savedInstanceState != null) { mStyle = savedInstanceState.getInt(SAVED_STYLE, STYLE_NORMAL); mTheme = savedInstanceState.getInt(SAVED_THEME, 0); mCancelable = savedInstanceState.getBoolean(SAVED_CANCELABLE, true); mShowsDialog = savedInstanceState.getBoolean(SAVED_SHOWS_DIALOG, mShowsDialog); mBackStackId = savedInstanceState.getInt(SAVED_BACK_STACK_ID, -1); } } /** @hide */ @Override public LayoutInflater getLayoutInflater(Bundle savedInstanceState) { if (!mShowsDialog) { return super.getLayoutInflater(savedInstanceState); } mDialog = onCreateDialog(savedInstanceState); switch (mStyle) { case STYLE_NO_INPUT: mDialog.getWindow().addFlags( WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE | WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE); // fall through... case STYLE_NO_FRAME: case STYLE_NO_TITLE: mDialog.requestWindowFeature(Window.FEATURE_NO_TITLE); } if (mDialog != null) { return (LayoutInflater) mDialog.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE); } return (LayoutInflater) getActivity().getSystemService(Context.LAYOUT_INFLATER_SERVICE); } /** * Override to build your own custom Dialog container. This is typically * used to show an AlertDialog instead of a generic Dialog; when doing so, * {@link #onCreateView(LayoutInflater, ViewGroup, Bundle)} does not need * to be implemented since the AlertDialog takes care of its own content. * <p> * This method will be called after {@link #onCreate(Bundle)} and before * {@link #onCreateView(LayoutInflater, ViewGroup, Bundle)}. The default implementation simply * instantiates and returns a {@link Dialog} class. * <p> * <em>Note: DialogFragment own the {@link Dialog#setOnCancelListener * Dialog.setOnCancelListener} and {@link Dialog#setOnDismissListener * Dialog.setOnDismissListener} callbacks. You must not set them yourself.</em> To find out * about these events, override {@link #onCancel(DialogInterface)} and * {@link #onDismiss(DialogInterface)}. * </p> * * @param savedInstanceState * The last saved instance state of the Fragment, * or null if this is a freshly created Fragment. * @return Return a new Dialog instance to be displayed by the Fragment. */ public Dialog onCreateDialog(Bundle savedInstanceState) { return new Dialog(getActivity(), getTheme()); } public void onCancel(DialogInterface dialog) { } public void onDismiss(DialogInterface dialog) { if (!mViewDestroyed) { // Note: we need to use allowStateLoss, because the dialog // dispatches this asynchronously so we can receive the call // after the activity is paused. Worst case, when the user comes // back to the activity they see the dialog again. dismissInternal(true); } } @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); if (!mShowsDialog) { return; } View view = getView(); if (view != null) { if (view.getParent() != null) { throw new IllegalStateException("DialogFragment can not be attached to a container view"); } mDialog.setContentView(view); } mDialog.setOwnerActivity(getActivity()); mDialog.setCancelable(mCancelable); mDialog.setOnCancelListener(this); mDialog.setOnDismissListener(this); if (savedInstanceState != null) { Bundle dialogState = savedInstanceState.getBundle(SAVED_DIALOG_STATE_TAG); if (dialogState != null) { mDialog.onRestoreInstanceState(dialogState); } } } @Override public void onStart() { super.onStart(); if (mDialog != null) { mViewDestroyed = false; mDialog.show(); } } @Override public void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); if (mDialog != null) { Bundle dialogState = mDialog.onSaveInstanceState(); if (dialogState != null) { outState.putBundle(SAVED_DIALOG_STATE_TAG, dialogState); } } if (mStyle != STYLE_NORMAL) { outState.putInt(SAVED_STYLE, mStyle); } if (mTheme != 0) { outState.putInt(SAVED_THEME, mTheme); } if (!mCancelable) { outState.putBoolean(SAVED_CANCELABLE, mCancelable); } if (!mShowsDialog) { outState.putBoolean(SAVED_SHOWS_DIALOG, mShowsDialog); } if (mBackStackId != -1) { outState.putInt(SAVED_BACK_STACK_ID, mBackStackId); } } @Override public void onStop() { super.onStop(); if (mDialog != null) { mDialog.hide(); } } /** * Remove dialog. */ @Override public void onDestroyView() { super.onDestroyView(); if (mDialog != null) { // Set removed here because this dismissal is just to hide // the dialog -- we don't want this to cause the fragment to // actually be removed. mViewDestroyed = true; mDialog.dismiss(); mDialog = null; } } }