CardMenuPopupHelper.java

package org.aisen.wen.component.cardmenu;

import android.content.Context;
import android.content.res.Resources;
import android.support.v7.view.menu.ListMenuItemView;
import android.support.v7.view.menu.MenuBuilder;
import android.support.v7.view.menu.MenuItemImpl;
import android.support.v7.view.menu.MenuView;
import android.support.v7.widget.ListPopupWindow;
import android.view.Gravity;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewTreeObserver;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.FrameLayout;
import android.widget.ListAdapter;
import android.widget.PopupWindow;

import org.aisen.wen.R;

import java.util.ArrayList;

/**
 * Created by wangdan on 16/9/13.
 */
class CardMenuPopupHelper implements AdapterView.OnItemClickListener, View.OnKeyListener,
                                                    ViewTreeObserver.OnGlobalLayoutListener, PopupWindow.OnDismissListener {

    static final int ITEM_LAYOUT = android.support.v7.appcompat.R.layout.abc_popup_menu_item_layout;

    private final Context mContext;
    private final LayoutInflater mInflater;
    private final int mPopupMaxWidth;
    private final int mPopupStyleAttr;
    private final int mPopupStyleRes;
    private final boolean mOverflowOnly;

    private View mAnchorView;
    private ListPopupWindow mPopup;
    private ViewTreeObserver mTreeObserver;

    private final MenuAdapter mAdapter;

    boolean mForceShowIcon;

    private int mDropDownGravity = Gravity.NO_GRAVITY;

    private ViewGroup mMeasureParent;

    /** Whether the cached content width value is valid. */
    private boolean mHasContentWidth;

    /** Cached content width from {@link #measureContentWidth}. */
    private int mContentWidth;

    private final MenuBuilder mMenu;

    private CardMenuOptions cardMenuOptions;

    CardMenuPopupHelper(Context context, MenuBuilder menu, CardMenuOptions cardMenuOptions,
                        View anchorView, boolean overflowOnly) {
        mContext = context;
        mMenu = menu;
        mInflater = LayoutInflater.from(context);
        mPopupStyleAttr = android.R.attr.actionOverflowMenuStyle;
        mPopupStyleRes = 0;
        mAdapter = new MenuAdapter(menu);
        mOverflowOnly = overflowOnly;
        final Resources res = context.getResources();
        mPopupMaxWidth = Math.max(res.getDisplayMetrics().widthPixels / 2,
                res.getDimensionPixelSize(R.dimen.abc_config_prefDialogWidth));
        mAnchorView = anchorView;
    }

    public void show() {
        if (!tryShow()) {
        }
    }

    final public boolean tryShow() {
        mPopup = new ListPopupWindow(mContext, null, mPopupStyleAttr, mPopupStyleRes);
        mPopup.setOnDismissListener(this);
        mPopup.setOnItemClickListener(this);
        mPopup.setAdapter(mAdapter);
        mPopup.setModal(true);

        View anchor = mAnchorView;
        if (anchor != null) {
            final boolean addGlobalListener = mTreeObserver == null;
            mTreeObserver = anchor.getViewTreeObserver(); // Refresh to latest
            if (addGlobalListener) mTreeObserver.addOnGlobalLayoutListener(this);
            mPopup.setAnchorView(anchor);

            if (cardMenuOptions != null) {
                if (cardMenuOptions.dropDownGravity != -1) {
                    mPopup.setDropDownGravity(cardMenuOptions.dropDownGravity);
                }
                else {
                    mPopup.setDropDownGravity(mDropDownGravity);
                }
                if (cardMenuOptions.dropDownHorizontalOffset > 0) {
                    mPopup.setHorizontalOffset(cardMenuOptions.dropDownHorizontalOffset);
                }
                if (cardMenuOptions.dropDownVerticalOffset > 0) {
                    mPopup.setVerticalOffset(cardMenuOptions.dropDownVerticalOffset);
                }
            }
            else {
                mPopup.setDropDownGravity(mDropDownGravity);
            }
        } else {
            return false;
        }

        if (!mHasContentWidth) {
            mContentWidth = measureContentWidth();
            mHasContentWidth = true;
        }

        mPopup.setContentWidth(mContentWidth);
        mPopup.setInputMethodMode(PopupWindow.INPUT_METHOD_NOT_NEEDED);
        mPopup.show();
        mPopup.getListView().setOnKeyListener(this);
        return true;
    }

    public void dismiss() {
        if (isShowing()) {
            mPopup.dismiss();
        }
    }

    public void onDismiss() {
        mPopup = null;
        if (mTreeObserver != null) {
            if (!mTreeObserver.isAlive()) mTreeObserver = mAnchorView.getViewTreeObserver();
            mTreeObserver.removeGlobalOnLayoutListener(this);
            mTreeObserver = null;
        }
    }

    public boolean isShowing() {
        return mPopup != null && mPopup.isShowing();
    }

    public void setGravity(int gravity) {
        mDropDownGravity = gravity;
    }

    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        MenuAdapter adapter = mAdapter;
        adapter.mAdapterMenu.performItemAction(adapter.getItem(position), 0);
    }

    public boolean onKey(View v, int keyCode, KeyEvent event) {
        if (event.getAction() == KeyEvent.ACTION_UP && keyCode == KeyEvent.KEYCODE_MENU) {
            dismiss();
            return true;
        }
        return false;
    }

    private int measureContentWidth() {
        // Menus don't tend to be long, so this is more sane than it looks.
        int maxWidth = 0;
        View itemView = null;
        int itemType = 0;

        final ListAdapter adapter = mAdapter;
        final int widthMeasureSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
        final int heightMeasureSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
        final int count = adapter.getCount();
        for (int i = 0; i < count; i++) {
            final int positionType = adapter.getItemViewType(i);
            if (positionType != itemType) {
                itemType = positionType;
                itemView = null;
            }

            if (mMeasureParent == null) {
                mMeasureParent = new FrameLayout(mContext);
            }

            itemView = adapter.getView(i, itemView, mMeasureParent);
            itemView.measure(widthMeasureSpec, heightMeasureSpec);

            final int itemWidth = itemView.getMeasuredWidth();
            if (itemWidth >= mPopupMaxWidth) {
                return mPopupMaxWidth;
            } else if (itemWidth > maxWidth) {
                maxWidth = itemWidth;
            }
        }

        return maxWidth;
    }

    @Override
    public void onGlobalLayout() {
        if (isShowing()) {
            final View anchor = mAnchorView;
            if (anchor == null || !anchor.isShown()) {
                dismiss();
            } else if (isShowing()) {
                // Recompute window size and position
                mPopup.show();
            }
        }
    }

    public void setForceShowIcon(boolean forceShow) {
        mForceShowIcon = forceShow;
    }

    private class MenuAdapter extends BaseAdapter {
        private MenuBuilder mAdapterMenu;
        private int mExpandedIndex = -1;

        public MenuAdapter(MenuBuilder menu) {
            mAdapterMenu = menu;
            findExpandedIndex();
        }

        public int getCount() {
            ArrayList<MenuItemImpl> items = mOverflowOnly ?
                    mAdapterMenu.getNonActionItems() : mAdapterMenu.getVisibleItems();
            if (mExpandedIndex < 0) {
                return items.size();
            }
            return items.size() - 1;
        }

        public MenuItemImpl getItem(int position) {
            ArrayList<MenuItemImpl> items = mOverflowOnly ?
                    mAdapterMenu.getNonActionItems() : mAdapterMenu.getVisibleItems();
            if (mExpandedIndex >= 0 && position >= mExpandedIndex) {
                position++;
            }
            return items.get(position);
        }

        public long getItemId(int position) {
            // Since a menu item's ID is optional, we'll use the position as an
            // ID for the item in the AdapterView
            return position;
        }

        public View getView(int position, View convertView, ViewGroup parent) {
            if (convertView == null) {
                convertView = mInflater.inflate(ITEM_LAYOUT, parent, false);
            }

            MenuView.ItemView itemView = (MenuView.ItemView) convertView;
            if (mForceShowIcon) {
                ((ListMenuItemView) convertView).setForceShowIcon(true);
            }
            itemView.initialize(getItem(position), 0);
            return convertView;
        }

        void findExpandedIndex() {
            final MenuItemImpl expandedItem = mMenu.getExpandedItem();
            if (expandedItem != null) {
                final ArrayList<MenuItemImpl> items = mMenu.getNonActionItems();
                final int count = items.size();
                for (int i = 0; i < count; i++) {
                    final MenuItemImpl item = items.get(i);
                    if (item == expandedItem) {
                        mExpandedIndex = i;
                        return;
                    }
                }
            }
            mExpandedIndex = -1;
        }

    }

}