Java tutorial
/* * Copyright (C) 2013 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.v7.app; import android.app.Activity; import android.content.Context; import android.content.ContextWrapper; import android.content.res.TypedArray; import android.graphics.Canvas; import android.graphics.Rect; import android.graphics.drawable.AnimationDrawable; import android.graphics.drawable.Drawable; import android.support.annotation.NonNull; import android.support.v4.app.FragmentActivity; import android.support.v4.app.FragmentManager; import android.support.v4.graphics.drawable.DrawableCompat; import android.support.v4.view.GravityCompat; import android.support.v7.media.MediaRouter; import android.support.v7.media.MediaRouteSelector; import android.support.v7.mediarouter.R; import android.text.TextUtils; import android.util.AttributeSet; import android.util.Log; import android.view.Gravity; import android.view.HapticFeedbackConstants; import android.view.SoundEffectConstants; import android.view.View; import android.widget.Toast; /** * The media route button allows the user to select routes and to control the * currently selected route. * <p> * The application must specify the kinds of routes that the user should be allowed * to select by specifying a {@link MediaRouteSelector selector} with the * {@link #setRouteSelector} method. * </p><p> * When the default route is selected or when the currently selected route does not * match the {@link #getRouteSelector() selector}, the button will appear in * an inactive state indicating that the application is not connected to a * route of the kind that it wants to use. Clicking on the button opens * a {@link MediaRouteChooserDialog} to allow the user to select a route. * If no non-default routes match the selector and it is not possible for an active * scan to discover any matching routes, then the button is disabled and cannot * be clicked. * </p><p> * When a non-default route is selected that matches the selector, the button will * appear in an active state indicating that the application is connected * to a route of the kind that it wants to use. The button may also appear * in an intermediary connecting state if the route is in the process of connecting * to the destination but has not yet completed doing so. In either case, clicking * on the button opens a {@link MediaRouteControllerDialog} to allow the user * to control or disconnect from the current route. * </p> * * <h3>Prerequisites</h3> * <p> * To use the media route button, the activity must be a subclass of * {@link FragmentActivity} from the <code>android.support.v4</code> * support library. Refer to support library documentation for details. * </p> * * @see MediaRouteActionProvider * @see #setRouteSelector */ public class MediaRouteButton extends View { private static final String TAG = "MediaRouteButton"; private static final String CHOOSER_FRAGMENT_TAG = "android.support.v7.mediarouter:MediaRouteChooserDialogFragment"; private static final String CONTROLLER_FRAGMENT_TAG = "android.support.v7.mediarouter:MediaRouteControllerDialogFragment"; private final MediaRouter mRouter; private final MediaRouterCallback mCallback; private MediaRouteSelector mSelector = MediaRouteSelector.EMPTY; private MediaRouteDialogFactory mDialogFactory = MediaRouteDialogFactory.getDefault(); private boolean mAttachedToWindow; private Drawable mRemoteIndicator; private boolean mRemoteActive; private boolean mCheatSheetEnabled; private boolean mIsConnecting; private int mMinWidth; private int mMinHeight; // The checked state is used when connected to a remote route. private static final int[] CHECKED_STATE_SET = { android.R.attr.state_checked }; // The checkable state is used while connecting to a remote route. private static final int[] CHECKABLE_STATE_SET = { android.R.attr.state_checkable }; public MediaRouteButton(Context context) { this(context, null); } public MediaRouteButton(Context context, AttributeSet attrs) { this(context, attrs, R.attr.mediaRouteButtonStyle); } public MediaRouteButton(Context context, AttributeSet attrs, int defStyleAttr) { super(MediaRouterThemeHelper.createThemedContext(context, defStyleAttr), attrs, defStyleAttr); context = getContext(); mRouter = MediaRouter.getInstance(context); mCallback = new MediaRouterCallback(); TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.MediaRouteButton, defStyleAttr, 0); setRemoteIndicatorDrawable(a.getDrawable(R.styleable.MediaRouteButton_externalRouteEnabledDrawable)); mMinWidth = a.getDimensionPixelSize(R.styleable.MediaRouteButton_android_minWidth, 0); mMinHeight = a.getDimensionPixelSize(R.styleable.MediaRouteButton_android_minHeight, 0); a.recycle(); setClickable(true); setLongClickable(true); } /** * Gets the media route selector for filtering the routes that the user can * select using the media route chooser dialog. * * @return The selector, never null. */ @NonNull public MediaRouteSelector getRouteSelector() { return mSelector; } /** * Sets the media route selector for filtering the routes that the user can * select using the media route chooser dialog. * * @param selector The selector, must not be null. */ public void setRouteSelector(MediaRouteSelector selector) { if (selector == null) { throw new IllegalArgumentException("selector must not be null"); } if (!mSelector.equals(selector)) { if (mAttachedToWindow) { if (!mSelector.isEmpty()) { mRouter.removeCallback(mCallback); } if (!selector.isEmpty()) { mRouter.addCallback(selector, mCallback); } } mSelector = selector; refreshRoute(); } } /** * Gets the media route dialog factory to use when showing the route chooser * or controller dialog. * * @return The dialog factory, never null. */ @NonNull public MediaRouteDialogFactory getDialogFactory() { return mDialogFactory; } /** * Sets the media route dialog factory to use when showing the route chooser * or controller dialog. * * @param factory The dialog factory, must not be null. */ public void setDialogFactory(@NonNull MediaRouteDialogFactory factory) { if (factory == null) { throw new IllegalArgumentException("factory must not be null"); } mDialogFactory = factory; } /** * Show the route chooser or controller dialog. * <p> * If the default route is selected or if the currently selected route does * not match the {@link #getRouteSelector selector}, then shows the route chooser dialog. * Otherwise, shows the route controller dialog to offer the user * a choice to disconnect from the route or perform other control actions * such as setting the route's volume. * </p><p> * The application can customize the dialogs by calling {@link #setDialogFactory} * to provide a customized dialog factory. * </p> * * @return True if the dialog was actually shown. * * @throws IllegalStateException if the activity is not a subclass of * {@link FragmentActivity}. */ public boolean showDialog() { if (!mAttachedToWindow) { return false; } final FragmentManager fm = getFragmentManager(); if (fm == null) { throw new IllegalStateException("The activity must be a subclass of FragmentActivity"); } MediaRouter.RouteInfo route = mRouter.getSelectedRoute(); if (route.isDefaultOrBluetooth() || !route.matchesSelector(mSelector)) { if (fm.findFragmentByTag(CHOOSER_FRAGMENT_TAG) != null) { Log.w(TAG, "showDialog(): Route chooser dialog already showing!"); return false; } MediaRouteChooserDialogFragment f = mDialogFactory.onCreateChooserDialogFragment(); f.setRouteSelector(mSelector); f.show(fm, CHOOSER_FRAGMENT_TAG); } else { if (fm.findFragmentByTag(CONTROLLER_FRAGMENT_TAG) != null) { Log.w(TAG, "showDialog(): Route controller dialog already showing!"); return false; } MediaRouteControllerDialogFragment f = mDialogFactory.onCreateControllerDialogFragment(); f.show(fm, CONTROLLER_FRAGMENT_TAG); } return true; } private FragmentManager getFragmentManager() { Activity activity = getActivity(); if (activity instanceof FragmentActivity) { return ((FragmentActivity) activity).getSupportFragmentManager(); } return null; } private Activity getActivity() { // Gross way of unwrapping the Activity so we can get the FragmentManager Context context = getContext(); while (context instanceof ContextWrapper) { if (context instanceof Activity) { return (Activity) context; } context = ((ContextWrapper) context).getBaseContext(); } return null; } /** * Sets whether to enable showing a toast with the content descriptor of the * button when the button is long pressed. */ void setCheatSheetEnabled(boolean enable) { mCheatSheetEnabled = enable; } @Override public boolean performClick() { // Send the appropriate accessibility events and call listeners boolean handled = super.performClick(); if (!handled) { playSoundEffect(SoundEffectConstants.CLICK); } return showDialog() || handled; } @Override public boolean performLongClick() { if (super.performLongClick()) { return true; } if (!mCheatSheetEnabled) { return false; } final CharSequence contentDesc = getContentDescription(); if (TextUtils.isEmpty(contentDesc)) { // Don't show the cheat sheet if we have no description return false; } final int[] screenPos = new int[2]; final Rect displayFrame = new Rect(); getLocationOnScreen(screenPos); getWindowVisibleDisplayFrame(displayFrame); final Context context = getContext(); final int width = getWidth(); final int height = getHeight(); final int midy = screenPos[1] + height / 2; final int screenWidth = context.getResources().getDisplayMetrics().widthPixels; Toast cheatSheet = Toast.makeText(context, contentDesc, Toast.LENGTH_SHORT); if (midy < displayFrame.height()) { // Show along the top; follow action buttons cheatSheet.setGravity(Gravity.TOP | GravityCompat.END, screenWidth - screenPos[0] - width / 2, height); } else { // Show along the bottom center cheatSheet.setGravity(Gravity.BOTTOM | Gravity.CENTER_HORIZONTAL, 0, height); } cheatSheet.show(); performHapticFeedback(HapticFeedbackConstants.LONG_PRESS); return true; } @Override protected int[] onCreateDrawableState(int extraSpace) { final int[] drawableState = super.onCreateDrawableState(extraSpace + 1); // Technically we should be handling this more completely, but these // are implementation details here. Checkable is used to express the connecting // drawable state and it's mutually exclusive with check for the purposes // of state selection here. if (mIsConnecting) { mergeDrawableStates(drawableState, CHECKABLE_STATE_SET); } else if (mRemoteActive) { mergeDrawableStates(drawableState, CHECKED_STATE_SET); } return drawableState; } @Override protected void drawableStateChanged() { super.drawableStateChanged(); if (mRemoteIndicator != null) { int[] myDrawableState = getDrawableState(); mRemoteIndicator.setState(myDrawableState); invalidate(); } } /** * Sets a drawable to use as the remote route indicator. */ public void setRemoteIndicatorDrawable(Drawable d) { if (mRemoteIndicator != null) { mRemoteIndicator.setCallback(null); unscheduleDrawable(mRemoteIndicator); } mRemoteIndicator = d; if (d != null) { d.setCallback(this); d.setState(getDrawableState()); d.setVisible(getVisibility() == VISIBLE, false); } refreshDrawableState(); } @Override protected boolean verifyDrawable(Drawable who) { return super.verifyDrawable(who) || who == mRemoteIndicator; } //@Override defined in v11 public void jumpDrawablesToCurrentState() { // We can't call super to handle the background so we do it ourselves. //super.jumpDrawablesToCurrentState(); if (getBackground() != null) { DrawableCompat.jumpToCurrentState(getBackground()); } // Handle our own remote indicator. if (mRemoteIndicator != null) { DrawableCompat.jumpToCurrentState(mRemoteIndicator); } } @Override public void setVisibility(int visibility) { super.setVisibility(visibility); if (mRemoteIndicator != null) { mRemoteIndicator.setVisible(getVisibility() == VISIBLE, false); } } @Override public void onAttachedToWindow() { super.onAttachedToWindow(); mAttachedToWindow = true; if (!mSelector.isEmpty()) { mRouter.addCallback(mSelector, mCallback); } refreshRoute(); } @Override public void onDetachedFromWindow() { mAttachedToWindow = false; if (!mSelector.isEmpty()) { mRouter.removeCallback(mCallback); } super.onDetachedFromWindow(); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { final int widthSize = MeasureSpec.getSize(widthMeasureSpec); final int heightSize = MeasureSpec.getSize(heightMeasureSpec); final int widthMode = MeasureSpec.getMode(widthMeasureSpec); final int heightMode = MeasureSpec.getMode(heightMeasureSpec); final int width = Math.max(mMinWidth, mRemoteIndicator != null ? mRemoteIndicator.getIntrinsicWidth() + getPaddingLeft() + getPaddingRight() : 0); final int height = Math.max(mMinHeight, mRemoteIndicator != null ? mRemoteIndicator.getIntrinsicHeight() + getPaddingTop() + getPaddingBottom() : 0); int measuredWidth; switch (widthMode) { case MeasureSpec.EXACTLY: measuredWidth = widthSize; break; case MeasureSpec.AT_MOST: measuredWidth = Math.min(widthSize, width); break; default: case MeasureSpec.UNSPECIFIED: measuredWidth = width; break; } int measuredHeight; switch (heightMode) { case MeasureSpec.EXACTLY: measuredHeight = heightSize; break; case MeasureSpec.AT_MOST: measuredHeight = Math.min(heightSize, height); break; default: case MeasureSpec.UNSPECIFIED: measuredHeight = height; break; } setMeasuredDimension(measuredWidth, measuredHeight); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); if (mRemoteIndicator != null) { final int left = getPaddingLeft(); final int right = getWidth() - getPaddingRight(); final int top = getPaddingTop(); final int bottom = getHeight() - getPaddingBottom(); final int drawWidth = mRemoteIndicator.getIntrinsicWidth(); final int drawHeight = mRemoteIndicator.getIntrinsicHeight(); final int drawLeft = left + (right - left - drawWidth) / 2; final int drawTop = top + (bottom - top - drawHeight) / 2; mRemoteIndicator.setBounds(drawLeft, drawTop, drawLeft + drawWidth, drawTop + drawHeight); mRemoteIndicator.draw(canvas); } } private void refreshRoute() { if (mAttachedToWindow) { final MediaRouter.RouteInfo route = mRouter.getSelectedRoute(); final boolean isRemote = !route.isDefaultOrBluetooth() && route.matchesSelector(mSelector); final boolean isConnecting = isRemote && route.isConnecting(); boolean needsRefresh = false; if (mRemoteActive != isRemote) { mRemoteActive = isRemote; needsRefresh = true; } if (mIsConnecting != isConnecting) { mIsConnecting = isConnecting; needsRefresh = true; } if (needsRefresh) { refreshDrawableState(); if (mRemoteIndicator.getCurrent() instanceof AnimationDrawable) { AnimationDrawable curDrawable = (AnimationDrawable) mRemoteIndicator.getCurrent(); if (!curDrawable.isRunning()) { curDrawable.start(); } } } } } private final class MediaRouterCallback extends MediaRouter.Callback { @Override public void onRouteAdded(MediaRouter router, MediaRouter.RouteInfo info) { refreshRoute(); } @Override public void onRouteRemoved(MediaRouter router, MediaRouter.RouteInfo info) { refreshRoute(); } @Override public void onRouteChanged(MediaRouter router, MediaRouter.RouteInfo info) { refreshRoute(); } @Override public void onRouteSelected(MediaRouter router, MediaRouter.RouteInfo info) { refreshRoute(); } @Override public void onRouteUnselected(MediaRouter router, MediaRouter.RouteInfo info) { refreshRoute(); } @Override public void onProviderAdded(MediaRouter router, MediaRouter.ProviderInfo provider) { refreshRoute(); } @Override public void onProviderRemoved(MediaRouter router, MediaRouter.ProviderInfo provider) { refreshRoute(); } @Override public void onProviderChanged(MediaRouter router, MediaRouter.ProviderInfo provider) { refreshRoute(); } } }