/* ********************************************************************** **
** Copyright notice **
** **
** (c) 2005-2006 RSSOwl Development Team **
** http://www.rssowl.org/ **
** **
** All rights reserved **
** **
** This program and the accompanying materials are made available under **
** the terms of the Eclipse Public License v1.0 which accompanies this **
** distribution, and is available at: **
** http://www.rssowl.org/legal/epl-v10.html **
** **
** A copy is found in the file epl-v10.html and important notices to the **
** license from the team is found in the textfile LICENSE.txt distributed **
** in this package. **
** **
** This copyright notice MUST APPEAR in all copies of the file! **
** **
** Contributors: **
** Eclipse.org - initial API and implementation **
** RSSOwl Development Team - minor changes **
** **
** ********************************************************************** */
package org.rssowl.ui.internal;
import org.eclipse.swt.SWT;
import org.eclipse.swt.SWTException;
import org.eclipse.swt.accessibility.ACC;
import org.eclipse.swt.accessibility.Accessible;
import org.eclipse.swt.accessibility.AccessibleAdapter;
import org.eclipse.swt.accessibility.AccessibleControlAdapter;
import org.eclipse.swt.accessibility.AccessibleControlEvent;
import org.eclipse.swt.accessibility.AccessibleEvent;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.events.PaintEvent;
import org.eclipse.swt.events.PaintListener;
import org.eclipse.swt.events.TraverseEvent;
import org.eclipse.swt.events.TraverseListener;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Canvas;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
/**
* A Label which supports aligned text and/or an image and different border
* styles.
* <p>
* If there is not enough space a CLabel uses the following strategy to fit the
* information into the available space:
*
* <pre>
* ignores the indent in left align mode
* shortens the text by replacing the center portion of the label with an ellipsis
* shortens the text by removing the center portion of the label
* </pre>
*
* <p>
* <dl>
* <dt><b>Styles:</b>
* <dd>LEFT, RIGHT, CENTER, SHADOW_IN, SHADOW_OUT, SHADOW_NONE</dd>
* <dt><b>Events:</b>
* <dd></dd>
* </dl>
* </p>
* <p>
* IMPORTANT: This class is <em>not</em> intended to be subclassed.
* </p>
*/
public class CCLabel extends Canvas {
/* Gap between icon and text */
private static final int GAP = 5;
/* Left and right margins */
private static final int INDENT = 3;
/* a string inserted in the middle of text that has been shortened */
private static final String ELLIPSIS = "..."; //$NON-NLS-1$ // could use the ellipsis glyph on some platforms "\u2026"
private static int DRAW_FLAGS = SWT.DRAW_MNEMONIC | SWT.DRAW_TAB | SWT.DRAW_TRANSPARENT | SWT.DRAW_DELIMITER;
/* the alignment. Either CENTER, RIGHT, LEFT. Default is LEFT */
private int align = SWT.LEFT;
private int hIndent = INDENT;
private int vIndent = INDENT;
/* the current text */
private String text;
/* the current icon */
private Image image;
private String appToolTipText;
private Image backgroundImage;
private Color[] gradientColors;
private int[] gradientPercents;
private boolean gradientVertical;
private Color background;
/**
* Constructs a new instance of this class given its parent and a style value
* describing its behavior and appearance.
* <p>
* The style value is either one of the style constants defined in class
* <code>SWT</code> which is applicable to instances of this class, or must
* be built by <em>bitwise OR</em>'ing together (that is, using the
* <code>int</code> "|" operator) two or more of those <code>SWT</code>
* style constants. The class description lists the style constants that are
* applicable to the class. Style bits are also inherited from superclasses.
* </p>
*
* @param parent a widget which will be the parent of the new instance (cannot
* be null)
* @param style the style of widget to construct
* @exception IllegalArgumentException
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
* </ul>
* @exception SWTException
* <ul>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that
* created the parent</li>
* </ul>
* @see SWT#LEFT
* @see SWT#RIGHT
* @see SWT#CENTER
* @see SWT#SHADOW_IN
* @see SWT#SHADOW_OUT
* @see SWT#SHADOW_NONE
* @see #getStyle()
*/
public CCLabel(Composite parent, int style) {
super(parent, checkStyle(style));
if ((style & (SWT.CENTER | SWT.RIGHT)) == 0)
style |= SWT.LEFT;
if ((style & SWT.CENTER) != 0)
align = SWT.CENTER;
if ((style & SWT.RIGHT) != 0)
align = SWT.RIGHT;
if ((style & SWT.LEFT) != 0)
align = SWT.LEFT;
addPaintListener(new PaintListener() {
public void paintControl(PaintEvent event) {
onPaint(event);
}
});
addDisposeListener(new DisposeListener() {
public void widgetDisposed(DisposeEvent event) {
onDispose();
}
});
addTraverseListener(new TraverseListener() {
public void keyTraversed(TraverseEvent event) {
if (event.detail == SWT.TRAVERSE_MNEMONIC) {
onMnemonic(event);
}
}
});
initAccessible();
}
/**
* Check the style bits to ensure that no invalid styles are applied.
*/
private static int checkStyle(int style) {
if ((style & SWT.BORDER) != 0)
style |= SWT.SHADOW_IN;
int mask = SWT.SHADOW_IN | SWT.SHADOW_OUT | SWT.SHADOW_NONE | SWT.LEFT_TO_RIGHT | SWT.RIGHT_TO_LEFT;
style = style & mask;
return style | SWT.NO_FOCUS | SWT.DOUBLE_BUFFERED;
}
/*
* @see org.eclipse.swt.widgets.Composite#computeSize(int, int, boolean)
*/
@Override
public Point computeSize(int wHint, int hHint, boolean changed) {
checkWidget();
Point e = getTotalSize(image, text);
if (wHint == SWT.DEFAULT) {
e.x += 2 * hIndent;
} else {
e.x = wHint;
}
if (hHint == SWT.DEFAULT) {
e.y += 2 * vIndent;
} else {
e.y = hHint;
}
return e;
}
/**
* Draw a rectangle in the given colors.
*/
private void drawBevelRect(GC gc, int x, int y, int w, int h, Color topleft, Color bottomright) {
gc.setForeground(bottomright);
gc.drawLine(x + w, y, x + w, y + h);
gc.drawLine(x, y + h, x + w, y + h);
gc.setForeground(topleft);
gc.drawLine(x, y, x + w - 1, y);
gc.drawLine(x, y, x, y + h - 1);
}
/*
* Return the lowercase of the first non-'&' character following an '&'
* character in the given string. If there are no '&' characters in the given
* string, return '\0'.
*/
char _findMnemonic(String string) {
if (string == null)
return '\0';
int index = 0;
int length = string.length();
do {
while (index < length && string.charAt(index) != '&')
index++;
if (++index >= length)
return '\0';
if (string.charAt(index) != '&')
return Character.toLowerCase(string.charAt(index));
index++;
} while (index < length);
return '\0';
}
/**
* Returns the alignment. The alignment style (LEFT, CENTER or RIGHT) is
* returned.
*
* @return SWT.LEFT, SWT.RIGHT or SWT.CENTER
*/
public int getAlignment() {
//checkWidget();
return align;
}
/**
* Return the CLabel's image or <code>null</code>.
*
* @return the image of the label or null
*/
public Image getImage() {
//checkWidget();
return image;
}
/**
* 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;
}
@Override
public int getStyle() {
int style = super.getStyle();
switch (align) {
case SWT.RIGHT:
style |= SWT.RIGHT;
break;
case SWT.CENTER:
style |= SWT.CENTER;
break;
case SWT.LEFT:
style |= SWT.LEFT;
break;
}
return style;
}
/**
* Return the Label's text.
*
* @return the text of the label or null
*/
public String getText() {
//checkWidget();
return text;
}
@Override
public String getToolTipText() {
checkWidget();
return appToolTipText;
}
private void initAccessible() {
Accessible accessible = getAccessible();
accessible.addAccessibleListener(new AccessibleAdapter() {
@Override
public void getName(AccessibleEvent e) {
e.result = getText();
}
@Override
public void getHelp(AccessibleEvent e) {
e.result = getToolTipText();
}
@Override
public void getKeyboardShortcut(AccessibleEvent e) {
char mnemonic = _findMnemonic(CCLabel.this.text);
if (mnemonic != '\0') {
e.result = "Alt+" + mnemonic; //$NON-NLS-1$
}
}
});
accessible.addAccessibleControlListener(new AccessibleControlAdapter() {
@Override
public void getChildAtPoint(AccessibleControlEvent e) {
e.childID = ACC.CHILDID_SELF;
}
@Override
public void getLocation(AccessibleControlEvent e) {
Rectangle rect = getDisplay().map(getParent(), null, getBounds());
e.x = rect.x;
e.y = rect.y;
e.width = rect.width;
e.height = rect.height;
}
@Override
public void getChildCount(AccessibleControlEvent e) {
e.detail = 0;
}
@Override
public void getRole(AccessibleControlEvent e) {
e.detail = ACC.ROLE_LABEL;
}
@Override
public void getState(AccessibleControlEvent e) {
e.detail = ACC.STATE_READONLY;
}
});
}
void onDispose() {
gradientColors = null;
gradientPercents = null;
backgroundImage = null;
text = null;
image = null;
appToolTipText = null;
}
void onMnemonic(TraverseEvent event) {
char mnemonic = _findMnemonic(text);
if (mnemonic == '\0')
return;
if (Character.toLowerCase(event.character) != mnemonic)
return;
Composite control = this.getParent();
while (control != null) {
Control[] children = control.getChildren();
int index = 0;
while (index < children.length) {
if (children[index] == this)
break;
index++;
}
index++;
if (index < children.length) {
if (children[index].setFocus()) {
event.doit = true;
event.detail = SWT.TRAVERSE_NONE;
}
}
control = control.getParent();
}
}
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 - 2 * hIndent);
Point extent = getTotalSize(img, t);
if (extent.x > availableWidth) {
availableWidth -= img != null ? img.getBounds().width : 0;
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 + hIndent;
if (align == SWT.CENTER) {
x = (rect.width - extent.x) / 2;
}
if (align == SWT.RIGHT) {
x = rect.width - hIndent - 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);
}
// draw the image
if (img != null) {
Rectangle imageRect = img.getBounds();
gc.drawImage(img, 0, 0, imageRect.width, imageRect.height, x, (rect.height - imageRect.height) / 2, imageRect.width, imageRect.height);
x += imageRect.width + GAP;
extent.x -= imageRect.width + GAP;
}
// draw the text
if (lines != null) {
int lineHeight = gc.getFontMetrics().getHeight();
int textHeight = lines.length * lineHeight;
int lineY = Math.max(vIndent, rect.y + (rect.height - textHeight) / 2);
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 - hIndent - lineWidth);
}
}
gc.drawText(lines[i], lineX, lineY, DRAW_FLAGS);
lineY += lineHeight;
}
}
}
/**
* Paint the Label's border.
*/
private void paintBorder(GC gc, Rectangle r) {
Display disp = getDisplay();
Color c1 = null;
Color c2 = null;
int style = getStyle();
if ((style & SWT.SHADOW_IN) != 0) {
c1 = disp.getSystemColor(SWT.COLOR_WIDGET_NORMAL_SHADOW);
c2 = disp.getSystemColor(SWT.COLOR_WIDGET_HIGHLIGHT_SHADOW);
}
if ((style & SWT.SHADOW_OUT) != 0) {
c1 = disp.getSystemColor(SWT.COLOR_WIDGET_LIGHT_SHADOW);
c2 = disp.getSystemColor(SWT.COLOR_WIDGET_NORMAL_SHADOW);
}
if (c1 != null && c2 != null) {
gc.setLineWidth(1);
drawBevelRect(gc, r.x, r.y, r.width - 1, r.height - 1, c1, c2);
}
}
/**
* Set the alignment of the CLabel. Use the values LEFT, CENTER and RIGHT to
* align image and text within the available space.
*
* @param align the alignment style of LEFT, RIGHT or CENTER
* @exception SWTException
* <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that
* created the receiver</li>
* <li>ERROR_INVALID_ARGUMENT - if the value of align is not one of SWT.LEFT,
* SWT.RIGHT or SWT.CENTER</li>
* </ul>
*/
public void setAlignment(int align) {
checkWidget();
if (align != SWT.LEFT && align != SWT.RIGHT && align != SWT.CENTER) {
SWT.error(SWT.ERROR_INVALID_ARGUMENT);
}
if (this.align != align) {
this.align = align;
redraw();
}
}
/*
* @see org.eclipse.swt.widgets.Control#setBackground(org.eclipse.swt.graphics.Color)
*/
@Override
public void setBackground(Color color) {
super.setBackground(color);
// Are these settings the same as before?
if (backgroundImage == null && gradientColors == null && gradientPercents == null) {
if (color == null) {
if (background == null)
return;
} else {
if (color.equals(background))
return;
}
}
background = color;
backgroundImage = null;
gradientColors = null;
gradientPercents = null;
redraw();
}
/**
* Specify a gradient of colours to be drawn in the background of the CLabel.
* <p>
* For example, to draw a gradient that varies from dark blue to blue and then
* to white and stays white for the right half of the label, use the following
* call to setBackground:
* </p>
*
* <pre>
* clabel.setBackground(new Color[]{display.getSystemColor(SWT.COLOR_DARK_BLUE),
* display.getSystemColor(SWT.COLOR_BLUE),
* display.getSystemColor(SWT.COLOR_WHITE),
* display.getSystemColor(SWT.COLOR_WHITE)},
* new int[] {25, 50, 100});
* </pre>
*
* @param colors an array of Color that specifies the colors to appear in the
* gradient in order of appearance from left to right; The value
* <code>null</code> clears the background gradient; the value
* <code>null</code> can be used inside the array of Color to specify the
* background color.
* @param percents an array of integers between 0 and 100 specifying the
* percent of the width of the widget at which the color should change; the
* size of the percents array must be one less than the size of the colors
* array.
* @exception SWTException
* <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that
* created the receiver</li>
* <li>ERROR_INVALID_ARGUMENT - if the values of colors and percents are not
* consistent</li>
* </ul>
*/
public void setBackground(Color[] colors, int[] percents) {
setBackground(colors, percents, false);
}
/**
* Specify a gradient of colours to be drawn in the background of the CLabel.
* <p>
* For example, to draw a gradient that varies from dark blue to white in the
* vertical, direction use the following call to setBackground:
* </p>
*
* <pre>
* clabel.setBackground(new Color[]{display.getSystemColor(SWT.COLOR_DARK_BLUE),
* display.getSystemColor(SWT.COLOR_WHITE)},
* new int[] {100}, true);
* </pre>
*
* @param colors an array of Color that specifies the colors to appear in the
* gradient in order of appearance from left/top to right/bottom; The value
* <code>null</code> clears the background gradient; the value
* <code>null</code> can be used inside the array of Color to specify the
* background color.
* @param percents an array of integers between 0 and 100 specifying the
* percent of the width/height of the widget at which the color should change;
* the size of the percents array must be one less than the size of the colors
* array.
* @param vertical indicate the direction of the gradient. True is vertical
* and false is horizontal.
* @exception SWTException
* <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that
* created the receiver</li>
* <li>ERROR_INVALID_ARGUMENT - if the values of colors and percents are not
* consistent</li>
* </ul>
* @since 3.0
*/
@SuppressWarnings("null")
public void setBackground(Color[] colors, int[] percents, boolean vertical) {
checkWidget();
if (colors != null) {
if (percents == null || percents.length != colors.length - 1) {
SWT.error(SWT.ERROR_INVALID_ARGUMENT);
}
if (getDisplay().getDepth() < 15) {
// Don't use gradients on low color displays
colors = new Color[] { colors[colors.length - 1] };
percents = new int[] { };
}
for (int i = 0; i < percents.length; i++) {
if (percents[i] < 0 || percents[i] > 100) {
SWT.error(SWT.ERROR_INVALID_ARGUMENT);
}
if (i > 0 && percents[i] < percents[i - 1]) {
SWT.error(SWT.ERROR_INVALID_ARGUMENT);
}
}
}
// Are these settings the same as before?
final Color background = getBackground();
if (backgroundImage == null) {
if ((gradientColors != null) && (colors != null) && (gradientColors.length == colors.length)) {
boolean same = false;
for (int i = 0; i < gradientColors.length; i++) {
same = (gradientColors[i] == colors[i]) || ((gradientColors[i] == null) && (colors[i] == background)) || ((gradientColors[i] == background) && (colors[i] == null));
if (!same)
break;
}
if (same) {
for (int i = 0; i < gradientPercents.length; i++) {
same = gradientPercents[i] == percents[i];
if (!same)
break;
}
}
if (same && this.gradientVertical == vertical)
return;
}
} else {
backgroundImage = null;
}
// Store the new settings
if (colors == null) {
gradientColors = null;
gradientPercents = null;
gradientVertical = false;
} else {
gradientColors = new Color[colors.length];
for (int i = 0; i < colors.length; ++i)
gradientColors[i] = (colors[i] != null) ? colors[i] : background;
gradientPercents = new int[percents.length];
for (int i = 0; i < percents.length; ++i)
gradientPercents[i] = percents[i];
gradientVertical = vertical;
}
// Refresh with the new settings
redraw();
}
/**
* Set the image to be drawn in the background of the label.
*
* @param image the image to be drawn in the background
* @exception SWTException
* <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that
* created the receiver</li>
* </ul>
*/
public void setBackground(Image image) {
checkWidget();
if (image == backgroundImage)
return;
if (image != null) {
gradientColors = null;
gradientPercents = null;
}
backgroundImage = image;
redraw();
}
/*
* @see org.eclipse.swt.widgets.Canvas#setFont(org.eclipse.swt.graphics.Font)
*/
@Override
public void setFont(Font font) {
super.setFont(font);
redraw();
}
/**
* Set the label's Image. The value <code>null</code> clears it.
*
* @param image the image to be displayed in the label or null
* @exception SWTException
* <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that
* created the receiver</li>
* </ul>
*/
public void setImage(Image image) {
checkWidget();
if (image != this.image) {
this.image = image;
redraw();
}
}
/**
* Set the label's text. The value <code>null</code> clears it.
*
* @param text the text to be displayed in the label or null
* @exception SWTException
* <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that
* created the receiver</li>
* </ul>
*/
public void setText(String text) {
checkWidget();
if (text == null)
text = ""; //$NON-NLS-1$
if (!text.equals(this.text)) {
this.text = text;
redraw();
}
}
/*
* @see org.eclipse.swt.widgets.Control#setToolTipText(java.lang.String)
*/
@Override
public void setToolTipText(String string) {
super.setToolTipText(string);
appToolTipText = super.getToolTipText();
}
/**
* 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;
while (min < mid && mid < max) {
String s1 = t.substring(0, mid);
String s2 = t.substring(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 = (max + min) / 2;
} else if (l1 + w + l2 < width) {
min = mid;
mid = (max + min) / 2;
} else {
min = max;
}
}
if (mid == 0)
return t;
return t.substring(0, mid) + ELLIPSIS + t.substring(l - mid, l);
}
private String[] splitString(String text) {
String[] lines = new String[1];
int start = 0, pos;
do {
pos = text.indexOf('\n', start);
if (pos == -1) {
lines[lines.length - 1] = text.substring(start);
} else {
boolean crlf = (pos > 0) && (text.charAt(pos - 1) == '\r');
lines[lines.length - 1] = text.substring(start, pos - (crlf ? 1 : 0));
start = pos + 1;
String[] newLines = new String[lines.length + 1];
System.arraycopy(lines, 0, newLines, 0, lines.length);
lines = newLines;
}
} while (pos != -1);
return lines;
}
}