diff --git a/src/api-impl/android/view/ViewStub.java b/src/api-impl/android/view/ViewStub.java index 4793b1cc..52ae719e 100644 --- a/src/api-impl/android/view/ViewStub.java +++ b/src/api-impl/android/view/ViewStub.java @@ -1,44 +1,199 @@ +/* + * Copyright (C) 2008 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.view; +import java.lang.ref.WeakReference; + +import com.android.internal.R; + import android.content.Context; import android.content.res.TypedArray; +import android.graphics.Canvas; import android.util.AttributeSet; -public class ViewStub extends View { +/** + * A ViewStub is an invisible, zero-sized View that can be used to lazily inflate + * layout resources at runtime. + * + * When a ViewStub is made visible, or when {@link #inflate()} is invoked, the layout resource + * is inflated. The ViewStub then replaces itself in its parent with the inflated View or Views. + * Therefore, the ViewStub exists in the view hierarchy until {@link #setVisibility(int)} or + * {@link #inflate()} is invoked. + * + * The inflated View is added to the ViewStub's parent with the ViewStub's layout + * parameters. Similarly, you can define/override the inflate View's id by using the + * ViewStub's inflatedId property. For instance: + * + *
+ *     <ViewStub android:id="@+id/stub"
+ *               android:inflatedId="@+id/subTree"
+ *               android:layout="@layout/mySubTree"
+ *               android:layout_width="120dip"
+ *               android:layout_height="40dip" />
+ * 
+ * + * The ViewStub thus defined can be found using the id "stub." After inflation of + * the layout resource "mySubTree," the ViewStub is removed from its parent. The + * View created by inflating the layout resource "mySubTree" can be found using the + * id "subTree," specified by the inflatedId property. The inflated View is finally + * assigned a width of 120dip and a height of 40dip. + * + * The preferred way to perform the inflation of the layout resource is the following: + * + *
+ *     ViewStub stub = (ViewStub) findViewById(R.id.stub);
+ *     View inflated = stub.inflate();
+ * 
+ * + * When {@link #inflate()} is invoked, the ViewStub is replaced by the inflated View + * and the inflated View is returned. This lets applications get a reference to the + * inflated View without executing an extra findViewById(). + * + * @attr ref android.R.styleable#ViewStub_inflatedId + * @attr ref android.R.styleable#ViewStub_layout + */ +public final class ViewStub extends View { + private int mLayoutResource = 0; + private int mInflatedId; - private int layoutResource; - private int inflatedId = View.NO_ID; + private WeakReference mInflatedViewRef; + + private LayoutInflater mInflater; + private OnInflateListener mInflateListener; + private boolean initialized = false; public ViewStub(Context context) { - this(context, null, 0); + super(context); + initialize(context); } - public ViewStub(Context context, AttributeSet attributeSet) { - this(context, attributeSet, 0); + /** + * Creates a new ViewStub with the specified layout resource. + * + * @param context The application's environment. + * @param layoutResource The reference to a layout resource that will be inflated. + */ + public ViewStub(Context context, int layoutResource) { + super(context); + mLayoutResource = layoutResource; + initialize(context); } - public ViewStub(Context context, AttributeSet attributeSet, int defStyle) { - super(context, attributeSet, defStyle); - TypedArray a = context.obtainStyledAttributes(attributeSet, com.android.internal.R.styleable.ViewStub); - layoutResource = a.getResourceId(com.android.internal.R.styleable.ViewStub_layout, -1); + public ViewStub(Context context, AttributeSet attrs) { + this(context, attrs, 0); + } + + @SuppressWarnings({"UnusedDeclaration"}) + public ViewStub(Context context, AttributeSet attrs, int defStyle) { + super(context, attrs, defStyle); + TypedArray a = context.obtainStyledAttributes(attrs, com.android.internal.R.styleable.ViewStub, + defStyle, 0); + + mInflatedId = a.getResourceId(R.styleable.ViewStub_inflatedId, NO_ID); + mLayoutResource = a.getResourceId(R.styleable.ViewStub_layout, 0); + a.recycle(); + + a = context.obtainStyledAttributes(attrs, com.android.internal.R.styleable.View, defStyle, 0); + id = a.getResourceId(R.styleable.View_id, NO_ID); + a.recycle(); + + initialize(context); } - public View inflate() { - if (layoutResource == -1) - throw new IllegalStateException("ViewStub must have a valid layoutResource"); - ViewGroup parent = (ViewGroup) getParent(); - View view = LayoutInflater.from(getContext()).inflate(layoutResource, parent, false); - if (inflatedId != View.NO_ID) - view.setId(inflatedId); - int index = parent.indexOfChild(this); - parent.removeView(this); - parent.addView(view, index, getLayoutParams()); - return view; + private void initialize(Context context) { + initialized = true; + setVisibility(GONE); + setWillNotDraw(true); } + /** + * Returns the id taken by the inflated view. If the inflated id is + * {@link View#NO_ID}, the inflated view keeps its original id. + * + * @return A positive integer used to identify the inflated view or + * {@link #NO_ID} if the inflated view should keep its id. + * + * @see #setInflatedId(int) + * @attr ref android.R.styleable#ViewStub_inflatedId + */ + public int getInflatedId() { + return mInflatedId; + } + + /** + * Defines the id taken by the inflated view. If the inflated id is + * {@link View#NO_ID}, the inflated view keeps its original id. + * + * @param inflatedId A positive integer used to identify the inflated view or + * {@link #NO_ID} if the inflated view should keep its id. + * + * @see #getInflatedId() + * @attr ref android.R.styleable#ViewStub_inflatedId + */ + public void setInflatedId(int inflatedId) { + mInflatedId = inflatedId; + } + + /** + * Returns the layout resource that will be used by {@link #setVisibility(int)} or + * {@link #inflate()} to replace this StubbedView + * in its parent by another view. + * + * @return The layout resource identifier used to inflate the new View. + * + * @see #setLayoutResource(int) + * @see #setVisibility(int) + * @see #inflate() + * @attr ref android.R.styleable#ViewStub_layout + */ + public int getLayoutResource() { + return mLayoutResource; + } + + /** + * Specifies the layout resource to inflate when this StubbedView becomes visible or invisible + * or when {@link #inflate()} is invoked. The View created by inflating the layout resource is + * used to replace this StubbedView in its parent. + * + * @param layoutResource A valid layout resource identifier (different from 0.) + * + * @see #getLayoutResource() + * @see #setVisibility(int) + * @see #inflate() + * @attr ref android.R.styleable#ViewStub_layout + */ public void setLayoutResource(int layoutResource) { - this.layoutResource = layoutResource; + mLayoutResource = layoutResource; + } + + /** + * Set {@link LayoutInflater} to use in {@link #inflate()}, or {@code null} + * to use the default. + */ + public void setLayoutInflater(LayoutInflater inflater) { + mInflater = inflater; + } + + /** + * Get current {@link LayoutInflater} used in {@link #inflate()}. + */ + public LayoutInflater getLayoutInflater() { + return mInflater; } @Override @@ -46,8 +201,121 @@ public class ViewStub extends View { setMeasuredDimension(0, 0); } - public void setInflatedId(int inflatedId) { - this.inflatedId = inflatedId; + @Override + public void draw(Canvas canvas) { } + @Override + protected void dispatchDraw(Canvas canvas) { + } + + /** + * When visibility is set to {@link #VISIBLE} or {@link #INVISIBLE}, + * {@link #inflate()} is invoked and this StubbedView is replaced in its parent + * by the inflated layout resource. After that calls to this function are passed + * through to the inflated view. + * + * @param visibility One of {@link #VISIBLE}, {@link #INVISIBLE}, or {@link #GONE}. + * + * @see #inflate() + */ + @Override + public void setVisibility(int visibility) { + if (!initialized) + return; + if (mInflatedViewRef != null) { + View view = mInflatedViewRef.get(); + if (view != null) { + view.setVisibility(visibility); + } else { + throw new IllegalStateException("setVisibility called on un-referenced view"); + } + } else { + super.setVisibility(visibility); + if (visibility == VISIBLE || visibility == INVISIBLE) { + inflate(); + } + } + } + + /** + * Inflates the layout resource identified by {@link #getLayoutResource()} + * and replaces this StubbedView in its parent by the inflated layout resource. + * + * @return The inflated layout resource. + * + */ + public View inflate() { + final ViewParent viewParent = getParent(); + + if (viewParent != null && viewParent instanceof ViewGroup) { + if (mLayoutResource != 0) { + final ViewGroup parent = (ViewGroup) viewParent; + final LayoutInflater factory; + if (mInflater != null) { + factory = mInflater; + } else { + factory = LayoutInflater.from(getContext()); + } + final View view = factory.inflate(mLayoutResource, parent, + false); + + if (mInflatedId != NO_ID) { + view.setId(mInflatedId); + } + + final int index = parent.indexOfChild(this); + parent.removeViewInLayout(this); + + final ViewGroup.LayoutParams layoutParams = getLayoutParams(); + if (layoutParams != null) { + parent.addView(view, index, layoutParams); + } else { + parent.addView(view, index); + } + + mInflatedViewRef = new WeakReference(view); + + if (mInflateListener != null) { + mInflateListener.onInflate(this, view); + } + + return view; + } else { + throw new IllegalArgumentException("ViewStub must have a valid layoutResource"); + } + } else { + throw new IllegalStateException("ViewStub must have a non-null ViewGroup viewParent"); + } + } + + /** + * Specifies the inflate listener to be notified after this ViewStub successfully + * inflated its layout resource. + * + * @param inflateListener The OnInflateListener to notify of successful inflation. + * + * @see android.view.ViewStub.OnInflateListener + */ + public void setOnInflateListener(OnInflateListener inflateListener) { + mInflateListener = inflateListener; + } + + /** + * Listener used to receive a notification after a ViewStub has successfully + * inflated its layout resource. + * + * @see android.view.ViewStub#setOnInflateListener(android.view.ViewStub.OnInflateListener) + */ + public static interface OnInflateListener { + /** + * Invoked after a ViewStub successfully inflated its layout resource. + * This method is invoked after the inflated view was added to the + * hierarchy but before the layout pass. + * + * @param stub The ViewStub that initiated the inflation. + * @param inflated The inflated View. + */ + void onInflate(ViewStub stub, View inflated); + } }