| /* |
| * Copyright (C) 2015 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 com.android.tools.idea.uibuilder.api; |
| |
| import com.android.annotations.NonNull; |
| import com.android.annotations.Nullable; |
| import com.android.tools.idea.uibuilder.model.FillPolicy; |
| import com.android.tools.idea.uibuilder.model.NlComponent; |
| import com.android.tools.idea.uibuilder.surface.ScreenView; |
| |
| import java.awt.*; |
| import java.util.EnumSet; |
| |
| /** A view handler is a tool handler for a given Android view class */ |
| public class ViewHandler { |
| /** |
| * Returns whether the given component accepts the given parent layout as a potential container |
| * |
| * @param layout the layout being inserted into (which does not yet contain the |
| * newly created node in its child list) |
| * @param newChild the newly created component |
| * @return true if the proposed parent is accepted |
| */ |
| public boolean acceptsParent(@NonNull NlComponent layout, |
| @NonNull NlComponent newChild) { |
| return true; |
| } |
| |
| /** |
| * Called when a view for this handler is being created. This allows for the handler to |
| * customize the newly created object. Note that this method is called not just when a |
| * view is created from a palette drag, but when views are constructed via a drag-move |
| * (where views are created in the destination and then deleted from the source), and |
| * even when views are constructed programmatically from other view handlers. The |
| * {@link InsertType} parameter can be used to distinguish the context for the |
| * insertion. For example, the <code>DialerFilterHandler</code> can insert EditText children |
| * when a DialerFilter is first created, but not during a copy/paste or a move. |
| * |
| * @param editor the associated editor |
| * @param parent the parent of the node, if any (which may not yet contain the newly created |
| * node in its child list) |
| * @param newChild the newly created node (which will always be a View that applies to |
| * this {@linkplain ViewHandler}) |
| * @param insertType whether this node was created as part of a newly created view, or |
| * @return true, or false if the view handler wants to cancel this component |
| * creation. This typically happens if for example the view handler tries |
| * to customize the component by for example asking the user for a specific |
| * resource (via {@link ViewEditor#displayResourceInput(EnumSet, String)}), |
| * and then the user cancels that dialog. At that point we don't want an |
| * unconfigured component lingering around, so the component create handler |
| * cancels the drop instead by returning false. |
| */ |
| public boolean onCreate(@NonNull ViewEditor editor, |
| @Nullable NlComponent parent, |
| @NonNull NlComponent newChild, |
| @NonNull InsertType insertType) { |
| return true; |
| } |
| |
| /** |
| * Paints the constraints for this component. If it returns true, it has handled |
| * the children as well. |
| * |
| * @param graphics the graphics to paint into |
| * @param component the component whose constraints we want to paint |
| * @return true if we're done with this component <b>and</b> it's children |
| */ |
| public boolean paintConstraints(@NonNull ScreenView screenView, @NonNull Graphics2D graphics, @NonNull NlComponent component) { |
| return false; |
| } |
| |
| public FillPolicy getFillPolicy() { |
| return FillPolicy.WIDTH_IN_VERTICAL; |
| } |
| } |