我尝试制作一个复合材料，我可以使用SWT.Tracker调整大小，这里是我的示例代码
final Composite b = new Composite(parent, SWT.NONE);
b.setBounds(20, 20, 80, 80);
b.setBackground(parent.getDisplay().getSystemColor(SWT.COLOR_BLUE));
b.addListener(SWT.MouseDown, new Listener() {
public void handleEvent(Event e) {
Tracker tracker = new Tracker(b.getParent(), SWT.RESIZE);
tracker.setStippled(true);
Rectangle rect = b.getBounds();
tracker.setRectangles(new Rectangle[] { rect });
if (tracker.open()) {
Rectangle after = tracker.getRectangles()[0];
b.setBounds(after);
}
tracker.dispose();
}
});
当我开始向左拖动时，光标会跳到合成的右边缘。当我开始向上拖动到底部时，光标跳到复合材料的底部边缘。我查看了该类的文档，但找不到任何设置来解决此问题。有人有指针吗？
答案 0 :(得分：3)
以下是解决方案：
在到达控件边缘时跟踪鼠标位置并显示正确的光标，然后相应地决定在Tracker构造函数中设置哪种样式。
保持任何边缘或角落的修剪区域，以便用户可以轻松输入Tracker。
例如，在X轴和Y轴上，您可以分别调用修剪xTrim=2和yTrim=2，以便在X轴上它将是2像素宽，在Y轴上将是3像素宽的行进入Tracker;
声明一个监听器，更改光标并相应地调用Tracker：
Listener resizeAndMoveListener = new Listener()
{
Point point = null;
public void handleEvent(Event event)
{
mousePoint = MouseInfo.getPointerInfo().getLocation();
sRect = shell.getBounds();
compoRect = composite.getBounds();
sRect = shell.getBounds();
compoRect = composite.getBounds();
topLeftX = sRect.x + compoRect.x + 8;
topLeftY = sRect.y + compoRect.y + 31;
topRightX = sRect.x + compoRect.x + compoRect.width + 7;
topRightY = sRect.y + compoRect.y + 31;
bottomLeftX = sRect.x + compoRect.x + 8;
bottomLeftY = sRect.y + compoRect.y + 31 + compoRect.height;
bottomRightX = sRect.x + compoRect.x + compoRect.width + 8;
bottomRightY = sRect.y + compoRect.y + 31 + compoRect.height;
xTrim = 2;
yTrim = 3;
switch (event.type)
{
case SWT.MouseDown:
// Top Left corner point
if (mousePoint.x >= topLeftX && mousePoint.x <= topLeftX + xTrim
&& mousePoint.y >= topLeftY && mousePoint.y <= topLeftY + xTrim)
{
shell.setCursor(CURSOR_SIZENE);
resizeAction = 1;
resizeStyle = SWT.TOP | SWT.LEFT;
}
// Top Edge
else if (mousePoint.x > topLeftX + xTrim && mousePoint.x < topRightX - xTrim && mousePoint.y >= topRightY && mousePoint.y <= topRightY + xTrim)
{
shell.setCursor(CURSOR_SIZEN);
resizeAction = 1;
resizeStyle = SWT.TOP;
}
// Top Right corner Point
else if (mousePoint.x >= topRightX - xTrim && mousePoint.x <= topRightX && mousePoint.y >= topRightY && mousePoint.y <= topRightY + xTrim)
{
shell.setCursor(CURSOR_SIZESE);
resizeAction = 1;
resizeStyle = SWT.TOP | SWT.RIGHT;
}
// Right edge
else if (mousePoint.x >= topRightX - xTrim && mousePoint.x <= topRightX
&& mousePoint.y > topRightY + xTrim && mousePoint.y < bottomRightY - xTrim)
{
shell.setCursor(CURSOR_SIZEE);
resizeAction = 1;
resizeStyle = SWT.RIGHT;
}
// Bottom Left corner
else if (mousePoint.x >= bottomLeftX && mousePoint.x <= bottomLeftX + xTrim
&& mousePoint.y >= bottomLeftY - xTrim && mousePoint.y <= bottomLeftY)
{
shell.setCursor(CURSOR_SIZESE);
resizeAction = 1;
resizeStyle = SWT.BOTTOM | SWT.LEFT;
}
// Left Edge
else if (mousePoint.x >= topLeftX && mousePoint.x <= topLeftX + xTrim
&& mousePoint.y > topLeftY + xTrim && mousePoint.y < bottomLeftY - xTrim)
{
shell.setCursor(CURSOR_SIZEE);
resizeAction = 1;
resizeStyle = SWT.LEFT;
}
// Bottom Right corner
else if (mousePoint.x >= bottomRightX - xTrim && mousePoint.x <= bottomRightX
&& mousePoint.y >= bottomRightY - xTrim && mousePoint.y <= bottomRightY)
{
shell.setCursor(CURSOR_SIZESE);
resizeAction = 1;
resizeStyle = SWT.BOTTOM | SWT.RIGHT;
}
// Bottom Edge
else if (mousePoint.x > bottomLeftX + xTrim && mousePoint.x < bottomRightX - xTrim
&& mousePoint.y > bottomRightY - yTrim && mousePoint.y < bottomRightY)
{
shell.setCursor(CURSOR_SIZEN);
resizeAction = 1;
resizeStyle = SWT.BOTTOM;
}
else
{
shell.setCursor(CURSOR_ARROW);
resizeAction = 0;
}
if (resizeAction == 1)
resize(event, resizeStyle);
else if (event.button == 1)
{
// prepare for moving when mouse button is down and resizeAction ==0
point = new Point(event.x, event.y);
}
break;
case SWT.MouseMove:
if (point == null)
break;
int x = point.x - event.x;
int y = point.y - event.y;
Control control = (Control) event.widget;
move(shell, control, x, y);
point = null;
break;
}
}
};
定义调整大小，即Tracker
：
void resize(Event event, final int STYLE)
{
Control control = (Control) event.widget;
tracker = new Tracker(control.getParent(), SWT.RESIZE | STYLE);
tracker.setStippled(true);
Rectangle rect = control.getBounds();
tracker.setRectangles(new Rectangle[] { rect });
if (tracker.open())
{
Rectangle after = tracker.getRectangles()[0];
control.setBounds(after);
}
tracker.dispose();
resizeAction = 0;
}
不要忘记在鼠标上发布Tracker：
Listener releaseTrackerListener = new Listener()
{
@Override
public void handleEvent(Event even)
{
resizeAction = 0;
tracker.dispose();
}
};
答案 1 :(得分：1)
如果您希望始终向右下方延伸，请将创建跟踪器的行更改为：
Tracker tracker = new Tracker(b.getParent(), SWT.RESIZE | SWT.RIGHT | SWT.DOWN);
您可以使用SWT.UP，SWT.DOWN，SWT.LEFT和SWT.RIGHT。
答案 2 :(得分：1)
AppWorks的解决方案非常出色。在shell上添加一个侦听器以设置从控件边界退出的光标，以便光标返回其原始箭头时，这也是一个好主意。