/*******************************************************************************
 * Copyright (c) 2000, 2010 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Stephan Michels, stephan@apache.org - 104944 [JUnit] Unnecessary code in JUnitProgressBar
 *******************************************************************************/
package org.simantics.tests.modelled.ui;

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.ControlAdapter;
import org.eclipse.swt.events.ControlEvent;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.events.PaintEvent;
import org.eclipse.swt.events.PaintListener;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Canvas;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;

/**
 * A progress bar with a red/green indication for success or failure.
 */
public class STSProgressBar extends Canvas {
    private static final int DEFAULT_WIDTH = 160;
    private static final int DEFAULT_HEIGHT = 18;

    private int fCurrentTickCount= 0;
    private int fMaxTickCount= 0;
    private int fColorBarWidth= 0;
    private Color fOKColor;
    private Color fFailureColor;
    private Color fStoppedColor;
    private boolean fError;
    private boolean fStopped= false;

    public STSProgressBar(Composite parent) {
        super(parent, SWT.NONE);

        addControlListener(new ControlAdapter() {
            @Override
            public void controlResized(ControlEvent e) {
                fColorBarWidth= scale(fCurrentTickCount);
                redraw();
            }
        });
        addPaintListener(new PaintListener() {
            public void paintControl(PaintEvent e) {
                paint(e);
            }
        });
        addDisposeListener(new DisposeListener() {
            public void widgetDisposed(DisposeEvent e) {
                fFailureColor.dispose();
                fOKColor.dispose();
                fStoppedColor.dispose();
            }
        });
        Display display= parent.getDisplay();
        fFailureColor= new Color(display, 159, 63, 63);
        fOKColor= new Color(display, 95, 191, 95);
        fStoppedColor= new Color(display, 120, 120, 120);
    }

    public void setMaximum(int max) {
        fMaxTickCount= max;
    }

    public void reset() {
        fError= false;
        fStopped= false;
        fCurrentTickCount= 0;
        fMaxTickCount= 0;
        fColorBarWidth= 0;
        redraw();
    }

    public void reset(boolean hasErrors, boolean stopped, int ticksDone, int maximum) {
        boolean noChange= fError == hasErrors && fStopped == stopped && fCurrentTickCount == ticksDone && fMaxTickCount == maximum;
        fError= hasErrors;
        fStopped= stopped;
        fCurrentTickCount= ticksDone;
        fMaxTickCount= maximum;
        fColorBarWidth= scale(ticksDone);
        if (! noChange)
            redraw();
    }

    private void paintStep(int startX, int endX) {
        GC gc = new GC(this);
        setStatusColor(gc);
        Rectangle rect= getClientArea();
        startX= Math.max(1, startX);
        gc.fillRectangle(startX, 1, endX-startX, rect.height-2);
        gc.dispose();
    }

    private void setStatusColor(GC gc) {
        if (fStopped)
            gc.setBackground(fStoppedColor);
        else if (fError)
            gc.setBackground(fFailureColor);
        else
            gc.setBackground(fOKColor);
    }

    public void stopped() {
        fStopped= true;
        redraw();
    }

    private int scale(int value) {
        if (fMaxTickCount > 0) {
            Rectangle r= getClientArea();
            if (r.width != 0)
                return Math.max(0, value*(r.width-2)/fMaxTickCount);
        }
        return value;
    }

    private void drawBevelRect(GC gc, int x, int y, int w, int h, Color topleft, Color bottomright) {
        gc.setForeground(topleft);
        gc.drawLine(x, y, x+w-1, y);
        gc.drawLine(x, y, x, y+h-1);

        gc.setForeground(bottomright);
        gc.drawLine(x+w, y, x+w, y+h);
        gc.drawLine(x, y+h, x+w, y+h);
    }

    private void paint(PaintEvent event) {
        GC gc = event.gc;
        Display disp= getDisplay();

        Rectangle rect= getClientArea();
        gc.fillRectangle(rect);
        drawBevelRect(gc, rect.x, rect.y, rect.width-1, rect.height-1,
            disp.getSystemColor(SWT.COLOR_WIDGET_NORMAL_SHADOW),
            disp.getSystemColor(SWT.COLOR_WIDGET_HIGHLIGHT_SHADOW));

        setStatusColor(gc);
        fColorBarWidth= Math.min(rect.width-2, fColorBarWidth);
        gc.fillRectangle(1, 1, fColorBarWidth, rect.height-2);
    }

    @Override
    public Point computeSize(int wHint, int hHint, boolean changed) {
        checkWidget();
        Point size= new Point(DEFAULT_WIDTH, DEFAULT_HEIGHT);
        if (wHint != SWT.DEFAULT) size.x= wHint;
        if (hHint != SWT.DEFAULT) size.y= hHint;
        return size;
    }

    public void step(int failures) {
        fCurrentTickCount++;
        int x= fColorBarWidth;

        fColorBarWidth= scale(fCurrentTickCount);

        if (!fError && failures > 0) {
            fError= true;
            x= 1;
        }
        if (fCurrentTickCount == fMaxTickCount)
            fColorBarWidth= getClientArea().width-1;
        paintStep(x, fColorBarWidth);
    }

    public void refresh(boolean hasErrors) {
        fError= hasErrors;
        redraw();
    }

}