Attachment 5236 Details for Bug 15054 – An improved version of TableVirtual

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An improved version of TableVirtual

TableVirtual.java (text/plain), 5.48 KB, created by Michael Scharf

on 2003-06-18 22:30:12 EDT

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Creator: Michael Scharf

Created: 2003-06-18 22:30:12 EDT

Size: 5.48 KB

patch

obsolete

>/**
> * @author Kosta
> * @author Michael.Scharf@windriver.com
> * source http://sourceforge.net/projects/eclipsecolorer/
> * Component Library
> * Modifications my Michael.Scharf@windriver.com
> */
>package org.eclipse.swt.widgets;
>import org.eclipse.swt.SWT;
>import org.eclipse.swt.graphics.Image;
>import org.eclipse.swt.internal.win32.LRESULT;
>import org.eclipse.swt.internal.win32.LVITEM;
>import org.eclipse.swt.internal.win32.NMHDR;
>import org.eclipse.swt.internal.win32.NMLISTVIEW;
>import org.eclipse.swt.internal.win32.OS;
>import org.eclipse.swt.internal.win32.TCHAR;
>public class TableVirtual extends Table {
>	/**
>	 * Interface to a virtual table label provider.
>	 * @author Michael.Scharf@windriver.com
>	 */
>	public interface IVirtualTableLabelProvider {
>		/**
>		 * Get the text associated with a specifeid table cell.
>		 * @param row
>		 * @param column
>		 * @return null or the text to be displayed in this cell. The text length will be 
>		 * truncated at 256 characters.
>		 */
>		String getColumnText(int row, int column);
>		/**
>		 * Get the image associated with a specifeid table cell.
>		 * @param row
>		 * @param column
>		 * @return null or the icon to be displayed in this cell.
>		 */
>		Image getColumnImage(int row, int column);
>	};
>	private IVirtualTableLabelProvider m_LabelProvider;
>	public TableVirtual(Composite parent, int style) {
>		super(parent, checkStyle(style));
>	}
>	/**
>	 * Sets the virtual lable provider for this VirtualTable.
>	 * @param labelProvider
>	 */
>	public void setVirtualLabelProvider(IVirtualTableLabelProvider labelProvider) {
>		m_LabelProvider = labelProvider;
>	}
>	int widgetStyle() {
>		int bits = super.widgetStyle();
>		bits |= 0x1000;
>		return bits;
>	}
>	void createItem(TableItem item, int index) {
>		// DO NOTHING!
>		// This is called by the constructor of TableItem and
>		// has some sideeffects we don't want for virtual tables...
>	}
>	/**
>	 * Create sets the number of rows of the virtual table.
>	 * @param cnt The number of cells of the virtual table.
>	 */
>	public void createItems(int cnt) {
>		// To save memory we allocate only ONE TableItam and share
>		// it for all cells. This is a trick to avoid the use of too much
>		// memory. Obvouisly, this breaks all TableItem related methods 
>		// inherited from Table. 
>		// TODO eliminate items totally and build a pure virtual table without the
>		// heritage of TableItem.
>		
>		// The allocation of items unnecessary memory overdead,
>		// but needed because Table relys on it.
>		items = new TableItem[cnt];
>		TableItem item = makeTableItem(0);
>		for (int i = 0; i < cnt; i++) {
>			// Comment this in to see the memory consumption difference...
>			// item = makeTableItem(i);
>			items[i] = item;
>		}
>		//
>		OS.SendMessage(handle, 0x1000 + 47, cnt, 0); // LVM_SETITEMCOUNT
>	}
>	/**
>	 * A little helper method to create TableItems
>	 * @param i
>	 * @return a new TableItem for position i
>	 */
>	private TableItem makeTableItem(int i) {
>		LVITEM lvItem = new LVITEM();
>		lvItem.iItem = i;
>		lvItem.iImage = OS.I_IMAGENONE;
>		lvItem.mask = OS.LVIF_IMAGE;
>		TableItem item=new TableItem(this, SWT.NONE);
>		return item;
>	}
>	LRESULT wmNotifyChild(int wParam, int lParam) {
>		NMHDR hdr = new NMHDR();
>		OS.MoveMemory(hdr, lParam, NMHDR.sizeof);
>		switch (hdr.code) {
>			case 0xFFFFFF4F: // LVN_GETDISPINFOW wide strings
>			//case 0xFFFFFF6A: // LVN_GETDISPINFOA win95 no wide strings (is this needed???)
>							 // see Microsoft Visual Studio/VC98/Include/COMMCTRL.H
>				{
>					NMLISTVIEW pnmlv = new NMLISTVIEW();
>					OS.MoveMemory(pnmlv, lParam, NMLISTVIEW.sizeof);
>					//
>					int item = pnmlv.iSubItem;
>					int column = pnmlv.uNewState;
>					if ((pnmlv.iItem & OS.LVIF_IMAGE) != 0) {
>						if ((m_LabelProvider != null) /*&& (column == 0)*/) {
>							Image image = m_LabelProvider.getColumnImage(item, column);
>							if (image != null) {
>								// because we don't have the datastructure
>								// we fake setting the icon integer by mapping it
>								// to an array of int
>								int[] data = new int[NMLISTVIEW.sizeof / 4];
>								OS.MoveMemory(data, lParam, NMLISTVIEW.sizeof);
>								// 10 is the position of the iImage
>								data[10] = imageIndex(image);
>								OS.MoveMemory(lParam, data, NMLISTVIEW.sizeof);
>							}
>						}
>					}
>					if ((pnmlv.iItem & OS.LVIF_TEXT) != 0) {
>						String string=null;
>						if (m_LabelProvider != null)
>							string = m_LabelProvider.getColumnText(item, column);
>						if(string!=null) {
>							if (string.length() > 256)
>								string = string.substring(0, 256);
>							TCHAR buffer = new TCHAR(getCodePage(), string, true);
>							int byteCount = buffer.length() * TCHAR.sizeof;
>							OS.MoveMemory(pnmlv.x, buffer, byteCount);
>						}
>					}
>				}
>		} // switch
>		return super.wmNotifyChild(wParam, lParam);
>	}
>	public void selectItem(int item) {
>		OS.SendMessage(handle, OS.LVM_GETITEMSTATE, item, OS.LVIS_SELECTED | OS.LVIS_FOCUSED);
>		LVITEM lvItem = new LVITEM();
>		lvItem.mask = OS.LVIF_STATE;
>		lvItem.stateMask = OS.LVIS_SELECTED | OS.LVIS_FOCUSED;
>		lvItem.state |= OS.LVIS_SELECTED | OS.LVIS_FOCUSED;
>		OS.SendMessage(handle, OS.LVM_SETITEMSTATE, item, lvItem);
>	}
>	/* (non-Javadoc)
>	 * @see org.eclipse.swt.widgets.Widget#releaseWidget()
>	 */
>	void releaseWidget() {
>		// Table.releaseWidget for huge tables was very slow because 
>		// it releases each of the virtual TableItams in items....
>		// Therefore we set the number of tableitems to 0 ;-)
>		createItems(0);
>		super.releaseWidget();
>	}
>
>}

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Attachments on bug 15054: 5236 | 5237