Toast.java

/* Copyright (c) 2002-2011 by XMLVM.org
 *
 * Project Info:  http://www.xmlvm.org
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA.
 */

package android.widget;

import java.util.LinkedList;

import android.content.Context;
import android.graphics.Typeface;
import android.internal.TopActivity;
import android.internal.XMLVMTheme;
import android.os.Handler;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup.LayoutParams;

public class Toast {

    public static final int                          LENGTH_LONG    = 1;
    public static final int                          LENGTH_SHORT   = 0;
    private int                                      duration;
    private View                                     view;
    private RelativeLayout                           metricsview;
    private final Context                            context;
    //
    // Toast display manager lock
    private static final Toast                       NO_TOAST;
    private static Toast                             lasttoast;
    private static final LinkedList<Toast>           registry;
    private static final RelativeLayout.LayoutParams layoutParams;

    private Handler                                  handler        = new Handler();
    private Runnable                                 cancelRunnable = new Runnable() {

                                                                        @Override
                                                                        public void run() {
                                                                            cancel();
                                                                        }
                                                                    };
    private Runnable                                 showRunnable   = new Runnable() {

                                                                        @Override
                                                                        public void run() {
                                                                            updateVisuals(true);
                                                                        }
                                                                    };

    static {
        registry = new LinkedList<Toast>();
        layoutParams = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT,
                LayoutParams.WRAP_CONTENT);
        layoutParams.addRule(RelativeLayout.CENTER_HORIZONTAL, RelativeLayout.TRUE);
        layoutParams.addRule(RelativeLayout.CENTER_VERTICAL, RelativeLayout.TRUE);
        NO_TOAST = new Toast(null);
        lasttoast = NO_TOAST;
    }


    public Toast(Context context) {
        this.context = context;
        duration = LENGTH_SHORT;
    }

    public static Toast makeText(Context context, int resId, int duration) {
        return makeText(context, context.getResources().getText(resId), duration);
    }

    public static Toast makeText(Context context, CharSequence text, int duration) {
        TextView textView = new TextView(context);
        textView.setBackgroundColor(XMLVMTheme.TOAST_COLOR);
        textView.setTextSize(16);
        textView.setTypeface(null, Typeface.BOLD);
        textView.setGravity(Gravity.CENTER);

        Toast toast = new Toast(context);
        toast.setView(textView);
        toast.setDuration(duration);
        toast.setText(text);
        return toast;
    }

    public void setText(CharSequence text) {
        if (view instanceof TextView) {
            ((TextView) view).setText(text);
        } else {
            throw new RuntimeException("This Toast was not created with Toast.makeText()");
        }
    }

    public void setView(View view) {
        this.view = view;
    }

    public void setGravity(int gravity, int xOffset, int yOffset) {
        if (view instanceof TextView) {
            ((TextView) view).setGravity(gravity);
        }
    }

    public void setDuration(int duration) {
        this.duration = duration;
    }

    public void show() {
        if (view != null) {
            TopActivity.get().runOnUiThread(showRunnable);
        }
    }

    public void cancel() {
        view = null;
        handler.removeCallbacks(cancelRunnable);
        handler.removeCallbacks(showRunnable);
        TopActivity.get().runOnUiThread(new Runnable() {

            @Override
            public void run() {
                updateVisuals(false);
            }
        });
    }

    private void updateVisuals(boolean setVisible) {
        synchronized (lasttoast) {
            if (setVisible) {
                if (lasttoast == NO_TOAST) {
                    showToastVisuals();
                }
                registry.offer(this);
            } else {
                registry.remove(this);
                if (lasttoast == this) {
                    if (metricsview != null) {
                        metricsview.getCommonView().removeFromSuperview();
                    }
                    if (registry.size() > 0) {
                        registry.peek().showToastVisuals();
                    } else {
                        lasttoast = NO_TOAST;
                    }
                }
            }
        }
    }

    private void showToastVisuals() {
        if (view != null) {
            handler.postDelayed(cancelRunnable, duration == LENGTH_SHORT ? 2000 : 4000);
            lasttoast = this;
            metricsview = new RelativeLayout(context);
            metricsview.addView(view, layoutParams);
            TopActivity.get().getWindow().xmlvmShowToast(metricsview);
        }
    }
}