1 /*
2  * Copyright (C) 2010 The Android Open Source Project
3  *
4  * Licensed under the Eclipse Public License, Version 1.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.eclipse.org/org/documents/epl-v10.php
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.ide.common.layout;
18 
19 import static com.android.SdkConstants.ANDROID_URI;
20 import static com.android.SdkConstants.ATTR_LAYOUT_HEIGHT;
21 import static com.android.SdkConstants.ATTR_LAYOUT_WIDTH;
22 import static com.android.SdkConstants.ATTR_ORIENTATION;
23 import static com.android.SdkConstants.FQCN_LINEAR_LAYOUT;
24 import static com.android.SdkConstants.VALUE_VERTICAL;
25 
26 import com.android.annotations.NonNull;
27 import com.android.annotations.Nullable;
28 import com.android.ide.common.api.DrawingStyle;
29 import com.android.ide.common.api.DropFeedback;
30 import com.android.ide.common.api.IDragElement;
31 import com.android.ide.common.api.IGraphics;
32 import com.android.ide.common.api.INode;
33 import com.android.ide.common.api.IViewRule;
34 import com.android.ide.common.api.InsertType;
35 import com.android.ide.common.api.Point;
36 import com.android.ide.common.api.Rect;
37 
38 /**
39  * An {@link IViewRule} for android.widget.ScrollView.
40  */
41 public class ScrollViewRule extends FrameLayoutRule {
42 
43     @Override
onChildInserted(@onNull INode child, @NonNull INode parent, @NonNull InsertType insertType)44     public void onChildInserted(@NonNull INode child, @NonNull INode parent,
45             @NonNull InsertType insertType) {
46         super.onChildInserted(child, parent, insertType);
47 
48         // The child of the ScrollView should fill in both directions
49         String fillParent = getFillParentValueName();
50         child.setAttribute(ANDROID_URI, ATTR_LAYOUT_WIDTH, fillParent);
51         child.setAttribute(ANDROID_URI, ATTR_LAYOUT_HEIGHT, fillParent);
52     }
53 
54     @Override
onCreate(@onNull INode node, @NonNull INode parent, @NonNull InsertType insertType)55     public void onCreate(@NonNull INode node, @NonNull INode parent,
56             @NonNull InsertType insertType) {
57         super.onCreate(node, parent, insertType);
58 
59         if (insertType.isCreate()) {
60             // Insert a default linear layout (which will in turn be registered as
61             // a child of this node and the create child method above will set its
62             // fill parent attributes, its id, etc.
63             INode linear = node.appendChild(FQCN_LINEAR_LAYOUT);
64             linear.setAttribute(ANDROID_URI, ATTR_ORIENTATION, VALUE_VERTICAL);
65         }
66     }
67 
68     @Override
onDropMove(@onNull INode targetNode, @NonNull IDragElement[] elements, @Nullable DropFeedback feedback, @NonNull Point p)69     public DropFeedback onDropMove(@NonNull INode targetNode, @NonNull IDragElement[] elements,
70             @Nullable DropFeedback feedback, @NonNull Point p) {
71         DropFeedback f = super.onDropMove(targetNode, elements, feedback, p);
72 
73         // ScrollViews only allow a single child
74         if (targetNode.getChildren().length > 0) {
75             f.invalidTarget = true;
76         }
77         return f;
78     }
79 
80     @Override
drawFeedback( IGraphics gc, INode targetNode, IDragElement[] elements, DropFeedback feedback)81     protected void drawFeedback(
82             IGraphics gc,
83             INode targetNode,
84             IDragElement[] elements,
85             DropFeedback feedback) {
86         if (targetNode.getChildren().length > 0) {
87             Rect b = targetNode.getBounds();
88             if (b.isValid()) {
89                 gc.useStyle(DrawingStyle.DROP_RECIPIENT);
90                 gc.drawRect(b);
91             }
92         } else {
93             super.drawFeedback(gc, targetNode, elements, feedback);
94         }
95     }
96 }
97