src/com/android/launcher2/Folder.java

/*
 * 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 com.android.launcher2;

import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.ObjectAnimator;
import android.animation.PropertyValuesHolder;
import android.animation.ValueAnimator;
import android.animation.ValueAnimator.AnimatorUpdateListener;
import android.content.Context;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.animation.AccelerateInterpolator;
import android.view.animation.DecelerateInterpolator;
import android.widget.AdapterView;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.AdapterView.OnItemLongClickListener;

import com.android.launcher.R;
import com.android.launcher2.FolderInfo.FolderListener;

import java.util.ArrayList;

/**
 * Represents a set of icons chosen by the user or generated by the system.
 */
public class Folder extends LinearLayout implements DragSource, OnItemLongClickListener,
        OnItemClickListener, OnClickListener, View.OnLongClickListener, DropTarget, FolderListener {

    protected DragController mDragController;

    protected Launcher mLauncher;

    protected FolderInfo mInfo;
    
    /**
     * Which item is being dragged
     */
    protected ShortcutInfo mDragItem;

    private static final String TAG = "Launcher.Folder";

    static final int STATE_NONE = -1;
    static final int STATE_SMALL = 0;
    static final int STATE_ANIMATING = 1;
    static final int STATE_OPEN = 2;

    private int mExpandDuration;
    protected CellLayout mContent;
    private final LayoutInflater mInflater;
    private final IconCache mIconCache;
    private int mState = STATE_NONE;
    private int[] mDragItemPosition = new int[2];
    private static final int FULL_GROW = 0;
    private static final int PARTIAL_GROW = 1;
    private int mMode = PARTIAL_GROW;
    private boolean mRearrangeOnClose = false;
    private FolderIcon mFolderIcon;
    private int mMaxCountX;
    private int mMaxCountY;
    private Rect mNewSize = new Rect();
    private ArrayList<View> mItemsInReadingOrder = new ArrayList<View>();
    private Drawable mIconDrawable;
    boolean mItemsInvalidated = false;
    ShortcutInfo mCurrentDragInfo;

    /**
     * Used to inflate the Workspace from XML.
     *
     * @param context The application's context.
     * @param attrs The attribtues set containing the Workspace's customization values.
     */
    public Folder(Context context, AttributeSet attrs) {
        super(context, attrs);
        setAlwaysDrawnWithCacheEnabled(false);
        mInflater = LayoutInflater.from(context);
        mIconCache = ((LauncherApplication)context.getApplicationContext()).getIconCache();
        mExpandDuration = getResources().getInteger(R.integer.config_folderAnimDuration);

        mMaxCountX = LauncherModel.getCellCountX() - 1;
        mMaxCountY = LauncherModel.getCellCountY() - 1;
    }

    @Override
    protected void onFinishInflate() {
        super.onFinishInflate();
        mContent = (CellLayout) findViewById(R.id.folder_content);
        mContent.setGridSize(0, 0);
        mContent.enableHardwareLayers();
    }

    public void onItemClick(AdapterView parent, View v, int position, long id) {
        ShortcutInfo app = (ShortcutInfo) parent.getItemAtPosition(position);
        int[] pos = new int[2];
        v.getLocationOnScreen(pos);
        app.intent.setSourceBounds(new Rect(pos[0], pos[1],
                pos[0] + v.getWidth(), pos[1] + v.getHeight()));
        mLauncher.startActivitySafely(app.intent, app);
    }

    public void onClick(View v) {
        Object tag = v.getTag();
        if (tag instanceof ShortcutInfo) {
            // refactor this code from Folder
            ShortcutInfo item = (ShortcutInfo) tag;
            int[] pos = new int[2];
            v.getLocationOnScreen(pos);
            item.intent.setSourceBounds(new Rect(pos[0], pos[1],
                    pos[0] + v.getWidth(), pos[1] + v.getHeight()));
            mLauncher.startActivitySafely(item.intent, item);
        }
    }

    public boolean onLongClick(View v) {
        Object tag = v.getTag();
        if (tag instanceof ShortcutInfo) {
            mLauncher.closeFolder(this);

            ShortcutInfo item = (ShortcutInfo) tag;
            if (!v.isInTouchMode()) {
                return false;
            }

            mLauncher.getWorkspace().onDragStartedWithItem(v);
            mDragController.startDrag(v, this, item, DragController.DRAG_ACTION_COPY);
            mDragItemPosition[0] = item.cellX;
            mDragItemPosition[1] = item.cellY;
            mIconDrawable = ((TextView) v).getCompoundDrawables()[1];

            mCurrentDragInfo = item;
            mItemsInvalidated = true;
            mInfo.itemsChanged();

            mDragItem = item;
        } else {
            mLauncher.closeFolder(this);
            mLauncher.showRenameDialog(mInfo);
        }
        return true;
    }

    public Drawable getDragDrawable() {
        return mIconDrawable;
    }

    /**
     * We need to handle touch events to prevent them from falling through to the workspace below.
     */
    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        return true;
    }

    public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
        if (!view.isInTouchMode()) {
            return false;
        }

        ShortcutInfo app = (ShortcutInfo) parent.getItemAtPosition(position);

        mDragController.startDrag(view, this, app, DragController.DRAG_ACTION_COPY);
        mLauncher.closeFolder(this);
        mDragItem = app;

        return true;
    }

    public void setDragController(DragController dragController) {
        mDragController = dragController;
    }

    public void onDragViewVisible() {
    }

    void setLauncher(Launcher launcher) {
        mLauncher = launcher;
    }

    void setFolderIcon(FolderIcon icon) {
        mFolderIcon = icon;
    }

    /**
     * @return the FolderInfo object associated with this folder
     */
    FolderInfo getInfo() {
        return mInfo;
    }

    void onOpen() {
        // When the folder opens, we need to refresh the GridView's selection by
        // forcing a layout
        // TODO: find out if this is still necessary
        mContent.requestLayout();
        requestFocus();
    }

    void onClose() {
        final Workspace workspace = mLauncher.getWorkspace();
        workspace.getChildAt(workspace.getCurrentPage()).requestFocus();
    }

    void bind(FolderInfo info) {
        mInfo = info;
        ArrayList<ShortcutInfo> children = info.contents;
        setupContentForNumItems(children.size());
        for (int i = 0; i < children.size(); i++) {
            ShortcutInfo child = (ShortcutInfo) children.get(i);
            createAndAddShortcut(child);
        }
        mItemsInvalidated = true;
        mInfo.addListener(this);
    }

    /**
     * Creates a new UserFolder, inflated from R.layout.user_folder.
     *
     * @param context The application's context.
     *
     * @return A new UserFolder.
     */
    static Folder fromXml(Context context) {
        return (Folder) LayoutInflater.from(context).inflate(R.layout.user_folder, null);
    }

    /**
     * This method is intended to make the UserFolder to be visually identical in size and position
     * to its associated FolderIcon. This allows for a seamless transition into the expanded state.
     */
    private void positionAndSizeAsIcon() {
        if (!(getParent() instanceof CellLayoutChildren)) return;

        CellLayout.LayoutParams iconLp = (CellLayout.LayoutParams) mFolderIcon.getLayoutParams();
        CellLayout.LayoutParams lp = (CellLayout.LayoutParams) getLayoutParams();

        if (mMode == PARTIAL_GROW) {
            setScaleX(0.8f);
            setScaleY(0.8f);
            setAlpha(0f);
        } else {
            lp.width = iconLp.width;
            lp.height = iconLp.height;
            lp.x = iconLp.x;
            lp.y = iconLp.y;
            mContent.setAlpha(0);
        }
        mState = STATE_SMALL;
    }

    public void animateOpen() {
        if (mState != STATE_SMALL) {
            positionAndSizeAsIcon();
        }
        if (!(getParent() instanceof CellLayoutChildren)) return;

        ObjectAnimator oa;
        CellLayout.LayoutParams lp = (CellLayout.LayoutParams) getLayoutParams();

        centerAboutIcon();
        if (mMode == PARTIAL_GROW) {
            PropertyValuesHolder alpha = PropertyValuesHolder.ofFloat("alpha", 1);
            PropertyValuesHolder scaleX = PropertyValuesHolder.ofFloat("scaleX", 1.0f);
            PropertyValuesHolder scaleY = PropertyValuesHolder.ofFloat("scaleY", 1.0f);
            oa = ObjectAnimator.ofPropertyValuesHolder(this, alpha, scaleX, scaleY);
        } else {
            PropertyValuesHolder width = PropertyValuesHolder.ofInt("width", mNewSize.width());
            PropertyValuesHolder height = PropertyValuesHolder.ofInt("height", mNewSize.height());
            PropertyValuesHolder x = PropertyValuesHolder.ofInt("x", mNewSize.left);
            PropertyValuesHolder y = PropertyValuesHolder.ofInt("y", mNewSize.top);
            oa = ObjectAnimator.ofPropertyValuesHolder(lp, width, height, x, y);
            oa.addUpdateListener(new AnimatorUpdateListener() {
                public void onAnimationUpdate(ValueAnimator animation) {
                    requestLayout();
                }
            });

            PropertyValuesHolder alpha = PropertyValuesHolder.ofFloat("alpha", 1.0f);
            ObjectAnimator alphaOa = ObjectAnimator.ofPropertyValuesHolder(mContent, alpha);
            alphaOa.setDuration(mExpandDuration);
            alphaOa.setInterpolator(new AccelerateInterpolator(2.0f));
            alphaOa.start();
        }

        oa.addListener(new AnimatorListenerAdapter() {
            @Override
            public void onAnimationStart(Animator animation) {
                mState = STATE_ANIMATING;
            }
            @Override
            public void onAnimationEnd(Animator animation) {
                mState = STATE_OPEN;
            }
        });
        oa.setDuration(mExpandDuration);
        oa.start();
    }

    public void animateClosed() {
        if (!(getParent() instanceof CellLayoutChildren)) return;

        CellLayoutChildren clc = (CellLayoutChildren) getParent();
        final CellLayout cellLayout = (CellLayout) clc.getParent();
        ObjectAnimator oa;

        if (mMode == PARTIAL_GROW) {
            PropertyValuesHolder alpha = PropertyValuesHolder.ofFloat("alpha", 0);
            PropertyValuesHolder scaleX = PropertyValuesHolder.ofFloat("scaleX", 0.9f);
            PropertyValuesHolder scaleY = PropertyValuesHolder.ofFloat("scaleY", 0.9f);
            oa = ObjectAnimator.ofPropertyValuesHolder(this, alpha, scaleX, scaleY);
        } else {
            CellLayout.LayoutParams iconLp = (CellLayout.LayoutParams) mFolderIcon.getLayoutParams();
            CellLayout.LayoutParams lp = (CellLayout.LayoutParams) getLayoutParams();

            PropertyValuesHolder width = PropertyValuesHolder.ofInt("width", iconLp.width);
            PropertyValuesHolder height = PropertyValuesHolder.ofInt("height", iconLp.height);
            PropertyValuesHolder x = PropertyValuesHolder.ofInt("x",iconLp.x);
            PropertyValuesHolder y = PropertyValuesHolder.ofInt("y", iconLp.y);
            oa = ObjectAnimator.ofPropertyValuesHolder(lp, width, height, x, y);
            oa.addUpdateListener(new AnimatorUpdateListener() {
                public void onAnimationUpdate(ValueAnimator animation) {
                    requestLayout();
                }
            });

            PropertyValuesHolder alpha = PropertyValuesHolder.ofFloat("alpha", 0f);
            ObjectAnimator alphaOa = ObjectAnimator.ofPropertyValuesHolder(mContent, alpha);
            alphaOa.setDuration(mExpandDuration);
            alphaOa.setInterpolator(new DecelerateInterpolator(2.0f));
            alphaOa.start();
        }

        oa.addListener(new AnimatorListenerAdapter() {
            @Override
            public void onAnimationEnd(Animator animation) {
                onCloseComplete();
                cellLayout.removeViewWithoutMarkingCells(Folder.this);
                mState = STATE_SMALL;
            }
            @Override
            public void onAnimationStart(Animator animation) {
                mState = STATE_ANIMATING;
            }
        });
        oa.setDuration(mExpandDuration);
        oa.start();
    }

    void notifyDataSetChanged() {
        // recreate all the children if the data set changes under us. We may want to do this more
        // intelligently (ie just removing the views that should no longer exist)
        mContent.removeAllViewsInLayout();
        bind(mInfo);
    }

    public boolean acceptDrop(DragObject d) {
        final ItemInfo item = (ItemInfo) d.dragInfo;
        final int itemType = item.itemType;
        return ((itemType == LauncherSettings.Favorites.ITEM_TYPE_APPLICATION ||
                    itemType == LauncherSettings.Favorites.ITEM_TYPE_SHORTCUT) &&
                    !isFull());
    }

    public void onDrop(DragObject d) {
        ShortcutInfo item;
        if (d.dragInfo instanceof ApplicationInfo) {
            // Came from all apps -- make a copy
            item = ((ApplicationInfo) d.dragInfo).makeShortcut();
            item.spanX = 1;
            item.spanY = 1;
        } else {
            item = (ShortcutInfo) d.dragInfo;
        }

        // Dragged from self onto self
        if (item == mCurrentDragInfo) {
            mInfo.remove(item);
        }

        mInfo.add(item);
    }

    protected boolean findAndSetEmptyCells(ShortcutInfo item) {
        int[] emptyCell = new int[2];
        if (mContent.findCellForSpan(emptyCell, item.spanX, item.spanY)) {
            item.cellX = emptyCell[0];
            item.cellY = emptyCell[1];
            return true;
        } else {
            return false;
        }
    }

    protected void createAndAddShortcut(ShortcutInfo item) {
        final TextView textView =
            (TextView) mInflater.inflate(R.layout.application_boxed, this, false);
        textView.setCompoundDrawablesWithIntrinsicBounds(null,
                new FastBitmapDrawable(item.getIcon(mIconCache)), null, null);
        textView.setText(item.title);
        textView.setTag(item);

        textView.setOnClickListener(this);
        textView.setOnLongClickListener(this);

        CellLayout.LayoutParams lp =
            new CellLayout.LayoutParams(item.cellX, item.cellY, item.spanX, item.spanY);
        boolean insert = false;
        mContent.addViewToCellLayout(textView, insert ? 0 : -1, (int)item.id, lp, true);
    }

    public void onDragEnter(DragObject d) {
        mContent.onDragEnter();
    }

    public void onDragOver(DragObject d) {
        float[] r = mapPointFromScreenToContent(d.x, d.y, null);
        mContent.visualizeDropLocation(null, null, (int) r[0], (int) r[1], 1, 1);
    }

    public void onDragExit(DragObject d) {
        mContent.onDragExit();
    }

    public float[] mapPointFromScreenToContent(int x, int y, float[] r) {
        if (r == null) {
            r = new float[2];
        }

        int[] screenLocation = new int[2];
        mContent.getLocationOnScreen(screenLocation);

        r[0] = x - screenLocation[0];
        r[1] = y - screenLocation[1];
        return r;
    }

    public void onDropCompleted(View target, DragObject d, boolean success) {
        if (!success) {
            if (d.dragView != null) {
                if (target instanceof CellLayout) {
                    // TODO: we should animate the item back to the folder in this case
                }
            }
            mCurrentDragInfo = null;
            mItemsInvalidated = true;
            mInfo.itemsChanged();
        } else {
            if (target != this) {
                mInfo.remove(mCurrentDragInfo);
                mCurrentDragInfo = null;
            }
        }
    }

    public boolean isDropEnabled() {
        return true;
    }

    public DropTarget getDropTargetDelegate(DragObject d) {
        return null;
    }

    private void setupContentDimension(int count) {
        ArrayList<View> list = getItemsInReadingOrder();

        int countX = mContent.getCountX();
        int countY = mContent.getCountY();
        boolean done = false;

        while (!done) {
            int oldCountX = countX;
            int oldCountY = countY;
            if (countX * countY < count) {
                // Current grid is too small, expand it
                if (countX <= countY && countX < mMaxCountX) {
                    countX++;
                } else if (countY < mMaxCountY) {
                    countY++;
                }
                if (countY == 0) countY++;
            } else if ((countY - 1) * countX >= count && countY >= countX) {
                countY = Math.max(0, countY - 1);
            } else if ((countX - 1) * countY >= count) {
                countX = Math.max(0, countX - 1);
            }
            done = countX == oldCountX && countY == oldCountY;
        }
        mContent.setGridSize(countX, countY);
        arrangeChildren(list);
    }

    public boolean isFull() {
        return getItemCount() >= mMaxCountX * mMaxCountY;
    }

    private void centerAboutIcon() {
        CellLayout.LayoutParams iconLp = (CellLayout.LayoutParams) mFolderIcon.getLayoutParams();
        CellLayout.LayoutParams lp = (CellLayout.LayoutParams) getLayoutParams();

        int width = getPaddingLeft() + getPaddingRight() + mContent.getDesiredWidth();
        int height = getPaddingTop() + getPaddingBottom() + mContent.getDesiredHeight();

        int centerX = iconLp.x + iconLp.width / 2;
        int centerY = iconLp.y + iconLp.height / 2;
        int centeredLeft = centerX - width / 2;
        int centeredTop = centerY - height / 2;

        CellLayoutChildren clc = (CellLayoutChildren) getParent();
        int parentWidth = 0;
        int parentHeight = 0;
        if (clc != null) {
            parentWidth = clc.getMeasuredWidth();
            parentHeight = clc.getMeasuredHeight();
        }

        int left = Math.min(Math.max(0, centeredLeft), parentWidth - width);
        int top = Math.min(Math.max(0, centeredTop), parentHeight - height);

        int folderPivotX = width / 2 + (centeredLeft - left);
        int folderPivotY = height / 2 + (centeredTop - top);
        setPivotX(folderPivotX);
        setPivotY(folderPivotY);
        int folderIconPivotX = (int) (mFolderIcon.getMeasuredWidth() *
                (1.0f * folderPivotX / width));
        int folderIconPivotY = (int) (mFolderIcon.getMeasuredHeight() *
                (1.0f * folderPivotY / height));
        mFolderIcon.setPivotX(folderIconPivotX);
        mFolderIcon.setPivotY(folderIconPivotY);

        if (mMode == PARTIAL_GROW) {
            lp.width = width;
            lp.height = height;
            lp.x = left;
            lp.y = top;
        } else {
            mNewSize.set(left, top, left + width, top + height);
        }
    }

    private void setupContentForNumItems(int count) {
        setupContentDimension(count);

        CellLayout.LayoutParams lp = (CellLayout.LayoutParams) getLayoutParams();
        if (lp == null) {
            lp = new CellLayout.LayoutParams(0, 0, -1, -1);
            lp.isLockedToGrid = false;
            setLayoutParams(lp);
        }
        centerAboutIcon();
    }

    private void arrangeChildren(ArrayList<View> list) {
        int[] vacant = new int[2];
        if (list == null) {
            list = getItemsInReadingOrder();
        }
        mContent.removeAllViews();

        for (int i = 0; i < list.size(); i++) {
            View v = list.get(i);
            mContent.getVacantCell(vacant, 1, 1);
            CellLayout.LayoutParams lp = (CellLayout.LayoutParams) v.getLayoutParams();
            lp.cellX = vacant[0];
            lp.cellY = vacant[1];
            ItemInfo info = (ItemInfo) v.getTag();
            info.cellX = vacant[0];
            info.cellY = vacant[1];
            boolean insert = false;
            mContent.addViewToCellLayout(v, insert ? 0 : -1, (int)info.id, lp, true);
            LauncherModel.addOrMoveItemInDatabase(mLauncher, info, mInfo.id, 0,
                    info.cellX, info.cellY);
        }
        mItemsInvalidated = true;
    }

    public void onAdd(ShortcutInfo item) {
        mItemsInvalidated = true;
        if (!findAndSetEmptyCells(item)) {
            // The current layout is full, can we expand it?
            setupContentForNumItems(getItemCount() + 1);
            findAndSetEmptyCells(item);
        }
        createAndAddShortcut(item);
        LauncherModel.addOrMoveItemInDatabase(
                mLauncher, item, mInfo.id, 0, item.cellX, item.cellY);
    }

    public int getItemCount() {
        return mContent.getChildrenLayout().getChildCount();
    }

    public View getItemAt(int index) {
        return mContent.getChildrenLayout().getChildAt(index);
    }

    private void onCloseComplete() {
        if (mRearrangeOnClose) {
            setupContentForNumItems(getItemCount());
            mRearrangeOnClose = false;
        }
    }

    public void onRemove(ShortcutInfo item) {
        mItemsInvalidated = true;
        View v = mContent.getChildAt(mDragItemPosition[0], mDragItemPosition[1]);
        mContent.removeView(v);
        if (mState == STATE_ANIMATING) {
            mRearrangeOnClose = true;
        } else {
            setupContentForNumItems(getItemCount());
        }
    }

    public void onItemsChanged() {
    }

    public ArrayList<View> getItemsInReadingOrder() {
        return getItemsInReadingOrder(true);
    }

    public ArrayList<View> getItemsInReadingOrder(boolean includeCurrentDragItem) {
        if (mItemsInvalidated) {
            mItemsInReadingOrder.clear();
            for (int j = 0; j < mContent.getCountY(); j++) {
                for (int i = 0; i < mContent.getCountX(); i++) {
                    View v = mContent.getChildAt(i, j);
                    if (v != null) {
                        ShortcutInfo info = (ShortcutInfo) v.getTag();
                        if (info != mCurrentDragInfo || includeCurrentDragItem) {
                            mItemsInReadingOrder.add(v);
                        }
                    }
                }
            }
            mItemsInvalidated = false;
        }
        return mItemsInReadingOrder;
    }
}