/** Adds scroll buttons to the tab bar */
private void addScrollButtons() {
scrollButtonsAdded = true;
final BoundedRangeModel hModel = viewport.getHModel();
ActionListener scrollListener =
new ActionListener() {
public void actionPerformed(ActionEvent event) {
if (event.getAction().equals("scroll_left")) {
// scroll left
hModel.setValue(hModel.getValue() - hModel.getScrollIncrement() / 4);
} else if (event.getAction().equals("scroll_right")) {
// scroll right
hModel.setValue(hModel.getValue() + hModel.getScrollIncrement() / 4);
}
}
};
final BButton left = new BButton("<", scrollListener, "scroll_left");
scrollingTabContainer.add(left, BorderLayout.WEST);
final BButton right = new BButton(">", scrollListener, "scroll_right");
scrollingTabContainer.add(right, BorderLayout.EAST);
hModel.addChangeListener(
new ChangeListener() {
public void stateChanged(ChangeEvent event) {
left.setEnabled(hModel.getValue() > hModel.getMinimum());
right.setEnabled(hModel.getValue() < hModel.getMaximum() - hModel.getExtent());
}
});
}
/**
* Adds a tab to diagram
*
* @param diagram
*/
protected void addTab(Diagram diagram) {
// do not add if tab already exists
if (getTab(diagram) != null) {
return;
}
// if the diagram key is null, and the exercise does not allow switching to the diagram type,
// do not create a tab for this diagram.
if (diagram.getKey() == null
&& !Exercise.getExercise().canSwitchToNullKeyDiagramType(diagram.getType())) {
return;
}
// no existing tab was found, so add a new one.
MainTab tab = new MainTab(diagram);
tabContainer.add(tab);
Dimension tabPreferredSize = tab.getPreferredSize(-1, -1);
tab.setSize(tabPreferredSize.width, tabPreferredSize.height);
tabs.add(tab);
viewport.layout();
BoundedRangeModel hModel = viewport.getHModel();
// if there are more tabs than will fit in the viewport, add the buttons for scrolling.
if (hModel.getRange() != hModel.getExtent() && !scrollButtonsAdded && hModel.getExtent() > 0) {
addScrollButtons();
viewport.layout();
}
}