Composite is slow to draw [message #762799] |
Thu, 08 December 2011 16:26 |
Oliver Buckley Messages: 1 Registered: December 2011 |
Junior Member |
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I'm creating a very simple class using SWT that essentially creates a grid of 96 cells. Each of these cells contains 3 buttons (split over two composites). The problem that I am having is that when the composite is drawn it is very slow (i.e. you can see the controls being drawn from bottom to top).
Is there a limit on the number of controls that you can sensibly use in a GridLayout or on a composite and I've just reached that limit (there's around 300 buttons, each of which has a composite associated with it). I've done something similar in Swing and it's fine...
I've attached a stripped down version of what I'm doing, hopefully someone can point me in the right direction?
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
public class GridComposite extends Composite {
private static final int ROWS = 12;
private static final int COLUMNS = 8;
public GridComposite(Composite parent, int style) {
super(parent, style);
setLayout(createGridLayout(COLUMNS, true));
Composite[] childComp = new Composite[COLUMNS * ROWS];
GridLayout parentLayout = createGridLayout(2, false);
GridLayout childLayout = createGridLayout(1, false);
for (int row = 0; row < ROWS; row++) {
for (int column = 0; column < COLUMNS; column++) {
String columnName = String.valueOf((char) (column+1 + 64));
int current = (row + column) + (row * (COLUMNS-1));
childComp[current] = new Composite(this, SWT.BORDER);
childComp[current].setLayout(parentLayout);
childComp[current].setLayoutData(new GridData());
Composite leftComposite = new Composite(childComp[current], SWT.NONE);
leftComposite.setLayout(childLayout);
leftComposite.setLayoutData(new GridData());
Button button = new Button(leftComposite, SWT.PUSH);
button.setLayoutData(new GridData(SWT.BEGINNING, SWT.CENTER, false, false));
button.setText(columnName + (row+1));
Composite rightComposite = new Composite(childComp[current], SWT.NONE);
rightComposite.setLayout(childLayout);
rightComposite.setLayoutData(new GridData());
Button button2 = new Button(rightComposite, SWT.PUSH);
button2.setLayoutData(new GridData(SWT.BEGINNING, SWT.CENTER, false, false));
button2.setText("o");
Button button3 = new Button(rightComposite, SWT.PUSH);
button3.setLayoutData(new GridData(SWT.BEGINNING, SWT.CENTER, false, false));
button3.setText("o");
}
}
}
private GridLayout createGridLayout(int columns, boolean makeColumnsEqual) {
GridLayout grid = new GridLayout(columns, makeColumnsEqual);
grid.horizontalSpacing = 0;
grid.verticalSpacing = 0;
grid.marginHeight = 0;
grid.marginWidth = 0;
return grid;
}
public static void main(String[] args) {
Display display = new Display();
Shell shell = new Shell(display);
shell.setLayout(new FillLayout());
GridComposite psc = new GridComposite(shell, SWT.NONE);
psc.setVisible(true);
shell.setLocation(400,400);
shell.pack();
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) shell.getDisplay().sleep();
}
display.dispose();
}
}
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