/**
* Determines the preferred span for this view along an axis.
*
* @param axis may be either View.X_AXIS or View.Y_AXIS
* @return the span the view would like to be rendered into >= 0. Typically the view is told to
* render into the span that is returned, although there is no guarantee. The parent may
* choose to resize or break the view.
*/
public float getPreferredSpan(int axis) {
switch (axis) {
case View.X_AXIS:
Segment buff = SegmentCache.getSharedSegment();
Document doc = getDocument();
int width;
try {
FontMetrics fm = getFontMetrics();
doc.getText(0, doc.getLength(), buff);
width = Utilities.getTabbedTextWidth(buff, fm, 0, this, 0);
if (buff.count > 0) {
Component c = getContainer();
firstLineOffset =
j86.sun.swing.SwingUtilities2.getLeftSideBearing(
(c instanceof JComponent) ? (JComponent) c : null, fm, buff.array[buff.offset]);
firstLineOffset = Math.max(0, -firstLineOffset);
} else {
firstLineOffset = 0;
}
} catch (BadLocationException bl) {
width = 0;
}
SegmentCache.releaseSharedSegment(buff);
return width + firstLineOffset;
default:
return super.getPreferredSpan(axis);
}
}
/**
* Update the visibility model with the associated JTextField (if there is one) to reflect the
* current visibility as a result of changes to the document model. The bounded range properties
* are updated. If the view hasn't yet been shown the extent will be zero and we just set it to be
* full until determined otherwise.
*/
void updateVisibilityModel() {
Component c = getContainer();
if (c instanceof JTextField) {
JTextField field = (JTextField) c;
BoundedRangeModel vis = field.getHorizontalVisibility();
int hspan = (int) getPreferredSpan(X_AXIS);
int extent = vis.getExtent();
int maximum = Math.max(hspan, extent);
extent = (extent == 0) ? maximum : extent;
int value = maximum - extent;
int oldValue = vis.getValue();
if ((oldValue + extent) > maximum) {
oldValue = maximum - extent;
}
value = Math.max(0, Math.min(value, oldValue));
vis.setRangeProperties(value, extent, 0, maximum, false);
}
}
/**
* Adjusts the allocation given to the view to be a suitable allocation for a text field. If the
* view has been allocated more than the preferred span vertically, the allocation is changed to
* be centered vertically. Horizontally the view is adjusted according to the horizontal alignment
* property set on the associated JTextField (if that is the type of the hosting component).
*
* @param a the allocation given to the view, which may need to be adjusted.
* @return the allocation that the superclass should use.
*/
protected Shape adjustAllocation(Shape a) {
if (a != null) {
Rectangle bounds = a.getBounds();
int vspan = (int) getPreferredSpan(Y_AXIS);
int hspan = (int) getPreferredSpan(X_AXIS);
if (bounds.height != vspan) {
int slop = bounds.height - vspan;
bounds.y += slop / 2;
bounds.height -= slop;
}
// horizontal adjustments
Component c = getContainer();
if (c instanceof JTextField) {
JTextField field = (JTextField) c;
BoundedRangeModel vis = field.getHorizontalVisibility();
int max = Math.max(hspan, bounds.width);
int value = vis.getValue();
int extent = Math.min(max, bounds.width - 1);
if ((value + extent) > max) {
value = max - extent;
}
vis.setRangeProperties(value, extent, vis.getMinimum(), max, false);
if (hspan < bounds.width) {
// horizontally align the interior
int slop = bounds.width - 1 - hspan;
int align = ((JTextField) c).getHorizontalAlignment();
if (Utilities.isLeftToRight(c)) {
if (align == LEADING) {
align = LEFT;
} else if (align == TRAILING) {
align = RIGHT;
}
} else {
if (align == LEADING) {
align = RIGHT;
} else if (align == TRAILING) {
align = LEFT;
}
}
switch (align) {
case SwingConstants.CENTER:
bounds.x += slop / 2;
bounds.width -= slop;
break;
case SwingConstants.RIGHT:
bounds.x += slop;
bounds.width -= slop;
break;
}
} else {
// adjust the allocation to match the bounded range.
bounds.width = hspan;
bounds.x -= vis.getValue();
}
}
return bounds;
}
return null;
}
