fixedcellrenderer.java

ktable 是一个由java开发的,对控制报表的项目,它最大的特点是使用独特的算法,能支持巨大的报表(千万以上?).

/*
 * Copyright (C) 2004 by Friederich Kupzog Elektronik & Software
 * 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

Authors: 
Friederich Kupzog,  [e-mail], www.kupzog.de/fkmk
Lorenz Maierhofer, [e-mail]

*/
package de.kupzog.ktable.renderers;

import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Display;

import de.kupzog.ktable.KTableModel;
import de.kupzog.ktable.KTableSortComparator;
import de.kupzog.ktable.KTableSortedModel;
import de.kupzog.ktable.SWTX;

/**
 * Class that provides an easy way of rendering a fixed cell.
 * <p>
 * Provided styles are at the moment: 
 * 
 * <ul>
 * <li><b>STYLE_FLAT</b> for a flat look.</li>
 * <li><b>STYLE_PUSH</b> for a button-like look.</li>
 * <li><b>INDICATION_SORT</b> if a sort indicator should be painted. Has only an effect 
 * when the <code>KTableModel</code> used is an
 * instance of <code>KTableSortedModel</code>. <br> 
 * Can be combined with <code>STYLE_FLAT</code> or <code>STYLE_PUSH</code> by or-ing.</li>
 * <li><b>INDICATION_FOCUS</b> when a focus bit should be colored differently. Combine by or-ing.
 * Note that the focus is only set to fixed cells when <code>
 * KTable.setHighlightSelectionInHeader(true)</code> is set.</li>
 * <li><b>INDICATION_FOCUS_ROW</b> when row-selection mode is on and the row highlighting should
 * be present in the fixed cell on the left. </li>
 * <li><b>INDICATION_CLICKED</b> shows a visible feedback when the user clicks on the cell.<br>
 * Only applicable if STYLE_PUSH is used.</li>
 * <li><b>SWT.BOLD</b> Makes the renderer draw bold text.</li>
 * <li><b>SWT.ITALIC</b> Makes the renderer draw italic text</li>
 * </ul>
 * 
 * @author Lorenz Maierhofer <[e-mail]>
 */
public class FixedCellRenderer extends DefaultCellRenderer {
    
    // some default images: 
    /** Small arrow pointing down. Can be used when displaying a sorting indicator. */
    public static final Image IMAGE_ARROWDOWN = SWTX.loadImageResource(
            Display.getCurrent(), 
            "/icons/arrow_down.gif");
    
    /** Small arrow pointing up. Can be used when displaying a sorting indicator */
    public static final Image IMAGE_ARROWUP = SWTX.loadImageResource(
            Display.getCurrent(), 
            "/icons/arrow_up.gif");
    
    public static final Color COLOR_FIXEDBACKGROUND = Display.getCurrent().getSystemColor(SWT.COLOR_WIDGET_BACKGROUND);
    
    /**
     * A constructor that lets the caller specify the style.
     * @param style The style that should be used to paint.<p>
     * - Use SWT.FLAT for a flat look.<br>
     * - Use SWT.PUSH for a button-like look. (default)<p>
     * The following additional indications can be activated: <br>
     * - INDICATION_FOCUS changes the background color if the fixed cell has focus.<br>
     * - INDICATION_FOCUS_ROW changes the background color so that it machtes with normal cells in rowselection mode.<br>
     * - INDICATION_SORT shows the sort direction when using a KTableSortedModel.<br>
     * - INDICATION_CLICKED shows a click feedback, if STYLE_PUSH is specified.
     * For text styles, the styles SWT.BOLD and SWT.ITALIC can be given.
     */
    public FixedCellRenderer(int style) {
        super(style);
        m_Style |= STYLE_PUSH;
    }
    
    /** 
     * Paint a box with or without a checked symbol.
     * 
     * @see de.kupzog.ktable.KTableCellRenderer#drawCell(GC, Rectangle, int, int, Object, boolean, boolean, boolean, KTableModel)
     */
    public void drawCell(GC gc, Rectangle rect, int col, int row, Object content, 
            boolean focus, boolean fixed, boolean clicked, KTableModel model) {
        applyFont(gc);
        
        // set up the colors:
        Color bgColor = getBackground();
        Color bottomBorderColor = COLOR_LINE_DARKGRAY;
        Color rightBorderColor = COLOR_LINE_DARKGRAY;
        Color fgColor = getForeground();
        if (focus && (m_Style & INDICATION_FOCUS)!=0) { 
            bgColor = COLOR_FIXEDHIGHLIGHT;
            bottomBorderColor = COLOR_TEXT;
            rightBorderColor = COLOR_TEXT;
        }
        if (focus && (m_Style & INDICATION_FOCUS_ROW) !=0) {
            bgColor = COLOR_BGROWFOCUS;
            bottomBorderColor = COLOR_BGROWFOCUS;
            rightBorderColor = COLOR_BGROWFOCUS;
            fgColor = COLOR_FGROWFOCUS;
        }        
               
        // STYLE_FLAT:
        if ((m_Style & STYLE_FLAT)!=0) {
            rect = drawDefaultSolidCellLine(gc, rect, bottomBorderColor, rightBorderColor);
            
            // draw content:
            drawCellContent(gc, rect, col, row, content, model, bgColor, fgColor);
            
        } else { // STYLE_PUSH
            drawCellButton(gc, rect, "", clicked && (m_Style & INDICATION_CLICKED)!=0);

            // push style border is drawn, exclude:
            rect.x+=2; 
            rect.y+=2;
            rect.width-=5;
            rect.height-=5;
            
            // draw content:
            drawCellContent(gc, rect, col, row, content, model, bgColor, fgColor);
        }
        resetFont(gc);
    }
    
    /**
     * Check for sort indicator and delegate content drawing to drawCellContent()
     */
    protected void drawCellContent(GC gc, Rectangle rect, int col, int row, Object content, 
            KTableModel model, Color bgColor, Color fgColor) {
        int oldWidth = rect.width;
        Image indicator = null;
        int x=0, y=0;
        
        if ((m_Style & INDICATION_SORT)!=0 &&  
                model instanceof KTableSortedModel && 
                ((KTableSortedModel)model).getSortColumn()==col &&
                model.getFixedHeaderRowCount()>row && row==0) {
            
            int sort = ((KTableSortedModel)model).getSortState();
            if (sort==KTableSortComparator.SORT_UP)
                indicator = IMAGE_ARROWDOWN;
            else if (sort==KTableSortComparator.SORT_DOWN)
                indicator = IMAGE_ARROWUP;
        
            if (indicator!=null) {
                int contentLength = rect.x+11+gc.stringExtent(content.toString()).x;
                x = rect.x+rect.width-8;
                if (contentLength<x)
                    x = contentLength;
                else  
                    rect.width-=indicator.getBounds().width+8;
                y = rect.y+rect.height/2-indicator.getBounds().height/2;
                
                //do not draw if there is not enough space for the image:
                if (rect.width+4<indicator.getBounds().width) {
                    rect.width+=indicator.getBounds().width+8;
                    indicator=null;
                }
            }
        }
        
        drawCellContent(gc, rect, content.toString(), null, 
                fgColor, 
                bgColor);
        
        // draw sort indicator:
        if (indicator!=null){
            gc.fillRectangle(rect.x+rect.width, rect.y, Math.min(indicator.getBounds().width+8, oldWidth-rect.width-1), rect.height);
            gc.drawImage(indicator, x, y);
        }
    }
    
    
    /**
     * Draws the cell as a button. It is visibly clickable and contains a button text.
     * All line borders of the cell are overpainted - there will not be any border between buttons. 
     * @param gc The GC to use when painting.
     * @param rect The cell area as given by KTable. (contains 1px bottom & right offset)
     * @param text The text to paint on the button. 
     * @param pressed Wether the button should be painted as clicked/pressed or not. 
     */
    protected void drawCellButton(GC gc, Rectangle rect, String text, boolean pressed) {
        rect.height += 1;
        rect.width += 1;
        gc.setForeground(Display.getCurrent().getSystemColor(
                SWT.COLOR_LIST_FOREGROUND));
        if (pressed) {
            SWTX.drawButtonDown(gc, 
                    text, getAlignment(),
                    null, getAlignment(), rect);
        } else {
            SWTX.drawButtonUp(gc, 
                    text, getAlignment(),
                    null, getAlignment(), rect);
        }
    }
    
    /**
     * @return returns the currently set background color.
     * If none was set, the default value is returned.
     */
    public Color getBackground() {
        if (m_bgColor!=null)
            return m_bgColor;
        return COLOR_FIXEDBACKGROUND;
    }
}