src/com/android/browser/addbookmark/FolderSpinner.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.browser.addbookmark;

import android.content.Context;
import android.view.View;
import android.util.AttributeSet;
import android.widget.AdapterView;
import android.widget.Spinner;

/**
 * Special Spinner class with its own callback for when the selection is set, which
 * can be ignored by calling setSelectionIgnoringSelectionChange
 */
public class FolderSpinner extends Spinner
        implements AdapterView.OnItemSelectedListener {
    private OnSetSelectionListener mOnSetSelectionListener;
    private boolean mFireSetSelection;

    /**
     * Callback for knowing when the selection has been manually set.  Does not
     * get called until the selected view has changed.
     */
    public interface OnSetSelectionListener {
        public void onSetSelection(long id);
    }

    public FolderSpinner(Context context, AttributeSet attrs) {
        super(context, attrs);
        super.setOnItemSelectedListener(this);
    }

    @Override
    public void setOnItemSelectedListener(AdapterView.OnItemSelectedListener l) {
        // Disallow setting an OnItemSelectedListener, since it is used by us
        // to fire onSetSelection.
        throw new RuntimeException("Cannot set an OnItemSelectedListener on a FolderSpinner");
    }

    public void setOnSetSelectionListener(OnSetSelectionListener l) {
        mOnSetSelectionListener = l;
    }

    /**
     * Call setSelection, without firing the callback
     * @param position New position to select.
     */
    public void setSelectionIgnoringSelectionChange(int position) {
        super.setSelection(position);
    }

    @Override
    public void setSelection(int position) {
        mFireSetSelection = true;
        int oldPosition = getSelectedItemPosition();
        super.setSelection(position);
        if (mOnSetSelectionListener != null) {
            if (oldPosition == position) {
                long id = getAdapter().getItemId(position);
                // Normally this is not called because the item did not actually
                // change, but in this case, we still want it to be called.
                onItemSelected(this, null, position, id);
            }
        }
    }

    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
        if (mFireSetSelection) {
            mOnSetSelectionListener.onSetSelection(id);
            mFireSetSelection = false;
        }
    }

    @Override
    public void onNothingSelected(AdapterView<?> parent) {}
}