/**
* Shorten the given text <code>t</code> so that its length doesn't exceed the given width. The
* default implementation replaces characters in the center of the original string with an
* ellipsis ("..."). Override if you need a different strategy.
*
* @param gc the gc to use for text measurement
* @param t the text to shorten
* @param width the width to shorten the text to, in pixels
* @return the shortened text
*/
protected String shortenText(GC gc, String t, int width) {
if (t == null) return null;
int w = gc.textExtent(ELLIPSIS, DRAW_FLAGS).x;
if (width <= w) return t;
int l = t.length();
int max = l / 2;
int min = 0;
int mid = (max + min) / 2 - 1;
if (mid <= 0) return t;
TextLayout layout = new TextLayout(getDisplay());
layout.setText(t);
mid = validateOffset(layout, mid);
while (min < mid && mid < max) {
String s1 = t.substring(0, mid);
String s2 = t.substring(validateOffset(layout, l - mid), l);
int l1 = gc.textExtent(s1, DRAW_FLAGS).x;
int l2 = gc.textExtent(s2, DRAW_FLAGS).x;
if (l1 + w + l2 > width) {
max = mid;
mid = validateOffset(layout, (max + min) / 2);
} else if (l1 + w + l2 < width) {
min = mid;
mid = validateOffset(layout, (max + min) / 2);
} else {
min = max;
}
}
String result =
mid == 0
? t
: t.substring(0, mid) + ELLIPSIS + t.substring(validateOffset(layout, l - mid), l);
layout.dispose();
return result;
}
/** Compute the minimum size. */
private Point getTotalSize(Image image, String text) {
Point size = new Point(0, 0);
if (image != null) {
Rectangle r = image.getBounds();
size.x += r.width;
size.y += r.height;
}
GC gc = new GC(this);
if (text != null && text.length() > 0) {
Point e = gc.textExtent(text, DRAW_FLAGS);
size.x += e.x;
size.y = Math.max(size.y, e.y);
if (image != null) size.x += GAP;
} else {
size.y = Math.max(size.y, gc.getFontMetrics().getHeight());
}
gc.dispose();
return size;
}
void onPaint(PaintEvent event) {
Rectangle rect = getClientArea();
if (rect.width == 0 || rect.height == 0) return;
boolean shortenText = false;
String t = text;
Image img = image;
int availableWidth = Math.max(0, rect.width - (leftMargin + rightMargin));
Point extent = getTotalSize(img, t);
if (extent.x > availableWidth) {
img = null;
extent = getTotalSize(img, t);
if (extent.x > availableWidth) {
shortenText = true;
}
}
GC gc = event.gc;
String[] lines = text == null ? null : splitString(text);
// shorten the text
if (shortenText) {
extent.x = 0;
for (int i = 0; i < lines.length; i++) {
Point e = gc.textExtent(lines[i], DRAW_FLAGS);
if (e.x > availableWidth) {
lines[i] = shortenText(gc, lines[i], availableWidth);
extent.x = Math.max(extent.x, getTotalSize(null, lines[i]).x);
} else {
extent.x = Math.max(extent.x, e.x);
}
}
if (appToolTipText == null) {
super.setToolTipText(text);
}
} else {
super.setToolTipText(appToolTipText);
}
// determine horizontal position
int x = rect.x + leftMargin;
if (align == SWT.CENTER) {
x = (rect.width - extent.x) / 2;
}
if (align == SWT.RIGHT) {
x = rect.width - rightMargin - extent.x;
}
// draw a background image behind the text
try {
if (backgroundImage != null) {
// draw a background image behind the text
Rectangle imageRect = backgroundImage.getBounds();
// tile image to fill space
gc.setBackground(getBackground());
gc.fillRectangle(rect);
int xPos = 0;
while (xPos < rect.width) {
int yPos = 0;
while (yPos < rect.height) {
gc.drawImage(backgroundImage, xPos, yPos);
yPos += imageRect.height;
}
xPos += imageRect.width;
}
} else if (gradientColors != null) {
// draw a gradient behind the text
final Color oldBackground = gc.getBackground();
if (gradientColors.length == 1) {
if (gradientColors[0] != null) gc.setBackground(gradientColors[0]);
gc.fillRectangle(0, 0, rect.width, rect.height);
} else {
final Color oldForeground = gc.getForeground();
Color lastColor = gradientColors[0];
if (lastColor == null) lastColor = oldBackground;
int pos = 0;
for (int i = 0; i < gradientPercents.length; ++i) {
gc.setForeground(lastColor);
lastColor = gradientColors[i + 1];
if (lastColor == null) lastColor = oldBackground;
gc.setBackground(lastColor);
if (gradientVertical) {
final int gradientHeight = (gradientPercents[i] * rect.height / 100) - pos;
gc.fillGradientRectangle(0, pos, rect.width, gradientHeight, true);
pos += gradientHeight;
} else {
final int gradientWidth = (gradientPercents[i] * rect.width / 100) - pos;
gc.fillGradientRectangle(pos, 0, gradientWidth, rect.height, false);
pos += gradientWidth;
}
}
if (gradientVertical && pos < rect.height) {
gc.setBackground(getBackground());
gc.fillRectangle(0, pos, rect.width, rect.height - pos);
}
if (!gradientVertical && pos < rect.width) {
gc.setBackground(getBackground());
gc.fillRectangle(pos, 0, rect.width - pos, rect.height);
}
gc.setForeground(oldForeground);
}
gc.setBackground(oldBackground);
} else {
if (background != null || (getStyle() & SWT.DOUBLE_BUFFERED) == 0) {
gc.setBackground(getBackground());
gc.fillRectangle(rect);
}
}
} catch (SWTException e) {
if ((getStyle() & SWT.DOUBLE_BUFFERED) == 0) {
gc.setBackground(getBackground());
gc.fillRectangle(rect);
}
}
// draw border
int style = getStyle();
if ((style & SWT.SHADOW_IN) != 0 || (style & SWT.SHADOW_OUT) != 0) {
paintBorder(gc, rect);
}
/*
* Compute text height and image height. If image height is more than
* the text height, draw image starting from top margin. Else draw text
* starting from top margin.
*/
Rectangle imageRect = null;
int lineHeight = 0, textHeight = 0, imageHeight = 0;
if (img != null) {
imageRect = img.getBounds();
imageHeight = imageRect.height;
}
if (lines != null) {
lineHeight = gc.getFontMetrics().getHeight();
textHeight = lines.length * lineHeight;
}
int imageY = 0, midPoint = 0, lineY = 0;
if (imageHeight > textHeight) {
if (topMargin == DEFAULT_MARGIN && bottomMargin == DEFAULT_MARGIN)
imageY = rect.y + (rect.height - imageHeight) / 2;
else imageY = topMargin;
midPoint = imageY + imageHeight / 2;
lineY = midPoint - textHeight / 2;
} else {
if (topMargin == DEFAULT_MARGIN && bottomMargin == DEFAULT_MARGIN)
lineY = rect.y + (rect.height - textHeight) / 2;
else lineY = topMargin;
midPoint = lineY + textHeight / 2;
imageY = midPoint - imageHeight / 2;
}
// draw the image
if (img != null) {
gc.drawImage(
img, 0, 0, imageRect.width, imageHeight, x, imageY, imageRect.width, imageHeight);
x += imageRect.width + GAP;
extent.x -= imageRect.width + GAP;
}
// draw the text
if (lines != null) {
gc.setForeground(getForeground());
for (int i = 0; i < lines.length; i++) {
int lineX = x;
if (lines.length > 1) {
if (align == SWT.CENTER) {
int lineWidth = gc.textExtent(lines[i], DRAW_FLAGS).x;
lineX = x + Math.max(0, (extent.x - lineWidth) / 2);
}
if (align == SWT.RIGHT) {
int lineWidth = gc.textExtent(lines[i], DRAW_FLAGS).x;
lineX = Math.max(x, rect.x + rect.width - rightMargin - lineWidth);
}
}
gc.drawText(lines[i], lineX, lineY, DRAW_FLAGS);
lineY += lineHeight;
}
}
}