src/com/android/launcher2/DeleteDropTarget.java

/*
 * 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 com.android.launcher2;

import android.animation.ObjectAnimator;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Color;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffColorFilter;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import com.android.launcher.R;

public class DeleteDropTarget extends ButtonDropTarget {

    private TextView mText;
    private int mHoverColor = 0xFFFF0000;

    public DeleteDropTarget(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public DeleteDropTarget(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    protected void onFinishInflate() {
        super.onFinishInflate();

        // Get the drawable
        mText = (TextView) findViewById(R.id.delete_target_text);

        // Get the hover color
        Resources r = getResources();
        mHoverColor = r.getColor(R.color.delete_target_hover_tint);
        mHoverPaint.setColorFilter(new PorterDuffColorFilter(
                mHoverColor, PorterDuff.Mode.SRC_ATOP));
        setBackgroundColor(mHoverColor);
        getBackground().setAlpha(0);
    }

    private boolean isAllAppsApplication(DragSource source, Object info) {
        return (source instanceof AppsCustomizePagedView) && (info instanceof ApplicationInfo);
    }
    private boolean isAllAppsWidget(DragSource source, Object info) {
        return (source instanceof AppsCustomizePagedView) && (info instanceof PendingAddWidgetInfo);
    }
    private boolean isWorkspaceApplication(DragObject d) {
        return (d.dragSource instanceof Workspace) && (d.dragInfo instanceof ShortcutInfo);
    }
    private boolean isWorkspaceWidget(DragObject d) {
        return (d.dragSource instanceof Workspace) && (d.dragInfo instanceof LauncherAppWidgetInfo);
    }
    private boolean isWorkspaceFolder(DragObject d) {
        return (d.dragSource instanceof Workspace) && (d.dragInfo instanceof FolderInfo);
    }

    @Override
    public boolean acceptDrop(DragObject d) {
        // We can remove everything including App shortcuts, folders, widgets, etc.
        return true;
    }

    @Override
    public void onDragStart(DragSource source, Object info, int dragAction) {
        boolean isVisible = true;
        boolean isUninstall = false;

        // If we are dragging a widget from AppsCustomize, hide the delete target
        if (isAllAppsWidget(source, info)) {
            isVisible = false;
        }

        // If we are dragging an application from AppsCustomize, only show the control if we can
        // delete the app (it was downloaded), and rename the string to "uninstall" in such a case
        if (isAllAppsApplication(source, info)) {
            ApplicationInfo appInfo = (ApplicationInfo) info;
            if ((appInfo.flags & ApplicationInfo.DOWNLOADED_FLAG) != 0) {
                isUninstall = true;
            } else {
                isVisible = false;
            }
        }

        mActive = isVisible;
        setVisibility(isVisible ? View.VISIBLE : View.GONE);
        if (mText.getText().length() > 0) {
            mText.setText(isUninstall ? R.string.delete_target_uninstall_label
                : R.string.delete_target_label);
        }
    }

    @Override
    public void onDragEnd() {
        super.onDragEnd();
        mActive = false;
    }

    public void onDragEnter(DragObject d) {
        super.onDragEnter(d);

        ObjectAnimator anim = ObjectAnimator.ofInt(getBackground(), "alpha",
                Color.alpha(mHoverColor));
        anim.setDuration(mTransitionDuration);
        anim.start();
    }

    public void onDragExit(DragObject d) {
        super.onDragExit(d);

        ObjectAnimator anim = ObjectAnimator.ofInt(getBackground(), "alpha", 0);
        anim.setDuration(mTransitionDuration);
        anim.start();
    }

    public void onDrop(DragObject d) {
        ItemInfo item = (ItemInfo) d.dragInfo;

        if (isAllAppsApplication(d.dragSource, item)) {
            // Uninstall the application if it is being dragged from AppsCustomize
            mLauncher.startApplicationUninstallActivity((ApplicationInfo) item);
        } else if (isWorkspaceApplication(d)) {
            LauncherModel.deleteItemFromDatabase(mLauncher, item);
        } else if (isWorkspaceFolder(d)) {
            // Remove the folder from the workspace and delete the contents from launcher model
            FolderInfo folderInfo = (FolderInfo) item;
            mLauncher.removeFolder(folderInfo);
            LauncherModel.deleteFolderContentsFromDatabase(mLauncher, folderInfo);
        } else if (isWorkspaceWidget(d)) {
            // Remove the widget from the workspace
            mLauncher.removeAppWidget((LauncherAppWidgetInfo) item);
            LauncherModel.deleteItemFromDatabase(mLauncher, item);

            final LauncherAppWidgetInfo launcherAppWidgetInfo = (LauncherAppWidgetInfo) item;
            final LauncherAppWidgetHost appWidgetHost = mLauncher.getAppWidgetHost();
            if (appWidgetHost != null) {
                // Deleting an app widget ID is a void call but writes to disk before returning
                // to the caller...
                new Thread("deleteAppWidgetId") {
                    public void run() {
                        appWidgetHost.deleteAppWidgetId(launcherAppWidgetInfo.appWidgetId);
                    }
                }.start();
            }
        }
    }
}