public void layoutContainer(Container parent) {
int tabPlacement = tabPane.getTabPlacement();
int tabCount = tabPane.getTabCount();
Insets insets = tabPane.getInsets();
int selectedIndex = tabPane.getSelectedIndex();
Component visibleComponent = getVisibleComponent();
calculateLayoutInfo();
if (selectedIndex < 0) {
if (visibleComponent != null) {
// The last tab was removed, so remove the component
setVisibleComponent(null);
}
} else {
Component selectedComponent = tabPane.getComponentAt(selectedIndex);
boolean shouldChangeFocus = false;
// In order to allow programs to use a single component
// as the display for multiple tabs, we will not change
// the visible compnent if the currently selected tab
// has a null component. This is a bit dicey, as we don't
// explicitly state we support this in the spec, but since
// programs are now depending on this, we're making it work.
//
if (selectedComponent != null) {
if (selectedComponent != visibleComponent && visibleComponent != null) {
if (SwingUtilities.findFocusOwner(visibleComponent) != null) {
shouldChangeFocus = true;
}
}
setVisibleComponent(selectedComponent);
}
int tx, ty, tw, th; // tab area bounds
int cx, cy, cw, ch; // content area bounds
Insets contentInsets = getContentBorderInsets(tabPlacement);
Rectangle bounds = tabPane.getBounds();
int numChildren = tabPane.getComponentCount();
if (numChildren > 0) {
// calculate tab area bounds
tw = bounds.width - insets.left - insets.right;
th = calculateTabAreaHeight(tabPlacement, runCount, maxTabHeight);
tx = insets.left;
ty = insets.top;
// calculate content area bounds
cx = tx + contentInsets.left;
cy = ty + th + contentInsets.top;
cw = bounds.width - insets.left - insets.right - contentInsets.left - contentInsets.right;
ch =
bounds.height
- insets.top
- insets.bottom
- th
- contentInsets.top
- contentInsets.bottom;
for (int i = 0; i < numChildren; i++) {
Component child = tabPane.getComponent(i);
if (child instanceof ScrollableTabViewport) {
JViewport viewport = (JViewport) child;
Rectangle viewRect = viewport.getViewRect();
int vw = tw;
int vh = th;
int totalTabWidth = rects[tabCount - 1].x + rects[tabCount - 1].width;
if (totalTabWidth > tw) {
// Need to allow space for scrollbuttons
vw = Math.max(tw - 36, 36);
;
if (totalTabWidth - viewRect.x <= vw) {
// Scrolled to the end, so ensure the
// viewport size is
// such that the scroll offset aligns with a
// tab
vw = totalTabWidth - viewRect.x;
}
}
child.setBounds(tx, ty, vw, vh);
} else if (child instanceof ScrollableTabButton) {
ScrollableTabButton scrollbutton = (ScrollableTabButton) child;
Dimension bsize = scrollbutton.getPreferredSize();
int bx = 0;
int by = 0;
int bw = bsize.width;
int bh = bsize.height;
boolean visible = false;
int totalTabWidth = rects[tabCount - 1].x + rects[tabCount - 1].width;
if (totalTabWidth > tw) {
int dir = scrollbutton.scrollsForward() ? EAST : WEST;
scrollbutton.setDirection(dir);
visible = true;
bx =
dir == EAST
? bounds.width - insets.left - bsize.width
: bounds.width - insets.left - 2 * bsize.width;
by = (tabPlacement == TOP ? ty + th - bsize.height : ty);
}
child.setVisible(visible);
if (visible) {
child.setBounds(bx, by, bw, bh);
}
} else {
// All content children...
child.setBounds(cx, cy, cw, ch);
}
}
if (shouldChangeFocus) {
if (!requestMyFocusForVisibleComponent()) {
tabPane.requestFocus();
}
}
}
}
}
