Cut,Copy,Paste

This article is out of date, please refer to http://books.zkoss.org/wiki/ZK_Spreadsheet_Essentials for more up to date information.

Purpose

ZK Spreadsheet uses Range to represent a cell, a row, a column, or selection of cells. We can use Range to get information or execute command. Here, we use Range to demonstrate how to implement cut, copy, and paste command.

Copy

1. We can construct Range object by Ranges. It has various functions, for example

Ranges.range(sheet, "A1:D4");

2. We can use AbstractComponent.getAttribute(String) to save the user's current selection range

private void setSource() {
	Rect selectedRect = spreadsheet.getSelection();
	Range range = Ranges.range(spreadsheet.getSelectedSheet(), 
				selectedRect.getTop(), 
				selectedRect.getLeft(), 
				selectedRect.getBottom(),
				selectedRect.getRight());

        //save user selection range
	spreadsheet.setAttribute(KEY_SOURCE_RANGE, range);
	spreadsheet.setAttribute(KEY_SOURCE_RECT, selectedRect);
	}

Cut

We can save a boolean object to distinguish between cut and paset command.
The reason why we need save this variable is because paste function needs to know whether it is cut or paste.
If it is cut, we need to clear the previous selection's content; if it is copy, we can keep the previous selection.

private void onCut() {
   spreadsheet.setAttribute(KEY_IS_CUT, Boolean.valueOf(true));
.....
}

private boolean isCut() {
	Boolean isCut = (Boolean)spreadsheet.getAttribute(KEY_IS_CUT);
	return isCut != null && isCut;
}

Paste

We can use Range.copy(Range) to copy the user's selection

1. Retrieve the user's previous selection. We can retrieve by AbstractComponent.getAttribute(String, Object), for example

private void onPaste() {
   Range srcRange = (Range)spreadsheet.getAttribute(KEY_SOURCE_RANGE);
   Rect srcRect = (Rect)spreadsheet.getAttribute(KEY_SOURCE_RECT);
....

2. Construct the destination Range object

After we get the previous selection range and current position, we can construct destination Range, and execute copy

int columnCount = srcRect.getRight() - srcRect.getLeft();
int rowCount = srcRect.getBottom() - srcRect.getTop();

Rect dstRect = spreadsheet.getSelection();
int rowIndex = dstRect.getTop();
int columnIndex = dstRect.getLeft();

Range dst = Ranges.range(spreadsheet.getSelectedSheet(),
					rowIndex, 
					columnIndex, 
					rowIndex + rowCount, 
					columnIndex + columnCount);
srcRange.copy(dst);

3. If command is cut, clear the highlight area of a spreadsheet and clear the previous selection's content.

private void clearCutRangeIfNeeded() {
	if (!isCut())
		return;
		
	Range srcRange = (Range)spreadsheet.getAttribute(KEY_SOURCE_RANGE);
	srcRange.clearContents();
	/* clear cell style*/
	CellStyle defaultCellStyle = spreadsheet.getBook().getCellStyleAt((short)0);
	srcRange.setStyle(defaultCellStyle);
}


private void clearHighlightIfNeeded() {
	if (isCut())
		spreadsheet.setHighlight(null);
}

ZUML

In zul, we declare a composer for event handling.

<zk>
	<div height="100%" width="100%" apply="demo.CopyPasteComposer">
		<spreadsheet id="spreadsheet" 
			src="/demo_sample.xls"
			maxrows="200" 
			maxcolumns="40" 
			vflex="1" 
			width="100%"
			ctrlKeys="^c^v^x">
		</spreadsheet>
		<menupopup id="cellMenu">
			<menuitem id="cutMenu" label="Cut" />
			<menuitem id="copyMenu" label="Copy" />
			<menuitem id="pasteMenu" label="Paste" />
		</menupopup>
	</div>
</zk>

Composer

In composer, we need to handle events, including onCellRightClick, Menuitem's onClick event and onCtrlKey event.

Here, we use GenericForwardComposer as it allow us to write intuitive onXxx$myid event handler methods and it can auto-wired variable.

Open Menu

onCellRightClick is a spreadsheet's event, this event occurs when the user right clicks on a cell. We use this event to popup menu, allowing users to select cut, copy or paste function.

Also, we can retrieve the mouse position from CellMouseEvent and set menupopup's popup position.

public void onCellRightClick$spreadsheet(CellMouseEvent event) {
	cellMenu.open(event.getClientx(),  event.getClienty());
}

Execute Command

We can register menuitem's onClick event to execute corresponding command.

public void onClick$cutMenu() {
	onCut();
}
	
public void onClick$copyMenu(Event evt) {
	onCopy();
}

public void onClick$pasteMenu(Event evt) {
	onPaste();
}

Use Control Key

We can also register control key event to execute corresponding command.

public void onCtrlKey$spreadsheet(KeyEvent evt) {
	if (evt.isCtrlKey()) {
		switch (evt.getKeyCode()) {
		case 'C':
			onCopy();
			break;
		case 'V':
			onPaste();
			break;
		case 'X':
			onCut();
			break;
		}
			
		}
	}

View the complete source of ZUML copyAndPaste.zul

View the complete source of composer CopyPasteComposer.java

Version History

Version	Date	Content

All source code listed in this book is at Github.