/** Repaints the area of the caret. */
private void repaintCaret() {
if (this.caret != null) {
// caret may be null when document is first set
Rectangle bounds = this.caret.getBounds();
this.hostComponent.repaint(
bounds.getX(), bounds.getY(), bounds.getWidth(), bounds.getHeight());
}
}
/**
* Calls layout() on the rootBox until the y-coordinate of a caret at the given offset converges,
* i.e. is less than LAYOUT_TOLERANCE pixels from the last call.
*
* @param offset Offset around which we should lay out boxes.
*/
private void iterateLayout(int offset) {
int repaintStart = Integer.MAX_VALUE;
int repaintEnd = 0;
Graphics g = this.hostComponent.createDefaultGraphics();
LayoutContext context = this.createLayoutContext(g);
int layoutY = this.rootBox.getCaret(context, offset).getY();
while (true) {
int oldLayoutY = layoutY;
IntRange repaintRange =
this.rootBox.layout(context, layoutY - LAYOUT_WINDOW / 2, layoutY + LAYOUT_WINDOW / 2);
if (repaintRange != null) {
repaintStart = Math.min(repaintStart, repaintRange.getStart());
repaintEnd = Math.max(repaintEnd, repaintRange.getEnd());
}
layoutY = this.rootBox.getCaret(context, offset).getY();
if (Math.abs(layoutY - oldLayoutY) < LAYOUT_TOLERANCE) {
break;
}
}
g.dispose();
if (repaintStart < repaintEnd) {
Rectangle viewport = this.hostComponent.getViewport();
if (repaintStart < viewport.getY() + viewport.getHeight() && repaintEnd > viewport.getY()) {
int start = Math.max(repaintStart, viewport.getY());
int end = Math.min(repaintEnd, viewport.getY() + viewport.getHeight());
this.hostComponent.repaint(viewport.getX(), start, viewport.getWidth(), end - start);
}
}
}
/**
* Repaints area of the control corresponding to a range of offsets in the document.
*
* @param startOffset Starting offset of the range.
* @param endOffset Ending offset of the range.
*/
private void repaintRange(int startOffset, int endOffset) {
Graphics g = this.hostComponent.createDefaultGraphics();
LayoutContext context = this.createLayoutContext(g);
Rectangle startBounds = this.rootBox.getCaret(context, startOffset).getBounds();
int top1 = startBounds.getY();
int bottom1 = top1 + startBounds.getHeight();
Rectangle endBounds = this.rootBox.getCaret(context, endOffset).getBounds();
int top2 = endBounds.getY();
int bottom2 = top2 + endBounds.getHeight();
int top = Math.min(top1, top2);
int bottom = Math.max(bottom1, bottom2);
if (top == bottom) {
// Account for zero-height horizontal carets
this.hostComponent.repaint(0, top - 1, this.getLayoutWidth(), bottom - top + 1);
} else {
this.hostComponent.repaint(0, top, this.getLayoutWidth(), bottom - top);
}
g.dispose();
}
/**
* Paints the contents of the widget in the given Graphics at the given point.
*
* @param g Graphics in which to draw the widget contents
* @param x x-coordinate at which to draw the widget
* @param y y-coordinate at which to draw the widget
*/
public void paint(Graphics g, int x, int y) {
if (this.rootBox == null) {
return;
}
LayoutContext context = this.createLayoutContext(g);
// Since we may be scrolling to sections of the document that have
// yet to be layed out, lay out any exposed area.
//
// TODO: this will probably be inaccurate, since we should really
// iterate the layout, but we don't have an offset around which
// to iterate...what to do, what to do....
Rectangle rect = g.getClipBounds();
int oldHeight = this.rootBox.getHeight();
this.rootBox.layout(context, rect.getY(), rect.getY() + rect.getHeight());
if (this.rootBox.getHeight() != oldHeight) {
this.hostComponent.setPreferredSize(this.rootBox.getWidth(), this.rootBox.getHeight());
}
this.rootBox.paint(context, 0, 0);
if (this.caretVisible) {
this.caret.draw(g, this.caretColor);
}
// Debug hash marks
/*
* ColorResource grey = g.createColor(new Color(160, 160, 160));
* ColorResource oldColor = g.setColor(grey); for (int y2 = rect.getY()
* - rect.getY() % 50; y2 < rect.getY() + rect.getHeight(); y2 += 50) {
* g.drawLine(x, y + y2, x+10, y + y2);
* g.drawString(Integer.toString(y2), x + 15, y + y2 - 10); }
* g.setColor(oldColor); grey.dispose();
*/
}
private void scrollCaretVisible() {
Rectangle caretBounds = this.caret.getBounds();
Rectangle viewport = this.hostComponent.getViewport();
int x = viewport.getX();
int y = 0;
int offset = getCaretOffset();
if (offset == 1) {
y = 0;
} else if (offset == getDocument().getLength() - 1) {
if (this.rootBox.getHeight() < viewport.getHeight()) {
y = 0;
} else {
y = this.rootBox.getHeight() - viewport.getHeight();
}
} else if (caretBounds.getY() < viewport.getY()) {
y = caretBounds.getY();
} else if (caretBounds.getY() + caretBounds.getHeight()
> viewport.getY() + viewport.getHeight()) {
y = caretBounds.getY() + caretBounds.getHeight() - viewport.getHeight();
} else {
// no scrolling required
return;
}
this.hostComponent.scrollTo(x, y);
}
/**
* Re-layout the entire widget, due to either a layout width change or a stylesheet range. This
* method does the actual setting of the width and stylesheet, since it needs to know where the
* caret is <i>before</i> the change, so that it can do a reasonable job of restoring the position
* of the viewport after the change.
*
* @param newWidth New width for the widget.
* @param newStyleSheet New stylesheet for the widget.
*/
private void relayoutAll(int newWidth, StyleSheet newStyleSheet) {
Graphics g = this.hostComponent.createDefaultGraphics();
LayoutContext context = this.createLayoutContext(g);
Rectangle viewport = this.hostComponent.getViewport();
// true if the caret is within the viewport
//
// TODO: incorrect if caret near the bottom and the viewport is
// shrinking
// To fix, we probably need to save the viewport height, just like
// we now store viewport width (as layout width).
boolean caretVisible = viewport.intersects(this.caret.getBounds());
// distance from the top of the viewport to the top of the caret
// use this if the caret is visible in the viewport
int relCaretY = 0;
// offset around which we are laying out
// this is also where we put the top of the viewport if the caret
// isn't visible
int offset;
if (caretVisible) {
relCaretY = this.caret.getY() - viewport.getY();
offset = this.getCaretOffset();
} else {
offset = this.rootBox.viewToModel(context, 0, viewport.getY());
}
this.layoutWidth = newWidth;
this.styleSheet = newStyleSheet;
// Re-create the context, since it holds the old stylesheet
context = this.createLayoutContext(g);
this.createRootBox();
this.iterateLayout(offset);
this.hostComponent.setPreferredSize(this.rootBox.getWidth(), this.rootBox.getHeight());
this.caret = this.rootBox.getCaret(context, this.getCaretOffset());
if (caretVisible) {
int viewportY = this.caret.getY() - Math.min(relCaretY, viewport.getHeight());
viewportY = Math.min(this.rootBox.getHeight() - viewport.getHeight(), viewportY);
viewportY = Math.max(0, viewportY); // this must appear after the
// above line, since
// that line might set viewportY negative
this.hostComponent.scrollTo(viewport.getX(), viewportY);
this.scrollCaretVisible();
} else {
int viewportY = this.rootBox.getCaret(context, offset).getY();
this.hostComponent.scrollTo(viewport.getX(), viewportY);
}
this.hostComponent.repaint();
g.dispose();
}