我有两个scrollpanel,尝试实现它们同时垂直滚动,这里是代码
//leftSide and rightSide class has scrollPanel
final ScrollPanel scrollPanelLeft = leftSide.getScrollPanel();
final ScrollPanel scrollPanelRight = rightSide.getScrollPanel();
leftSide.removeMouseHandlers();
leftSide.removeScrollHandler();
HandlerRegistration mouseWheelScrollHandler =
scrollPanelLeft.addDomHandler(new MouseWheelHandler() {
@Override
public void onMouseWheel(MouseWheelEvent event) {
int currentVertPos =
scrollPanelLeft.getVerticalScrollPosition();
if (!lockSide)
scrollPanelRight.setVerticalScrollPosition(currentVertPos);
}
}, MouseWheelEvent.getType());
leftSide.addScrollHandler(mouseWheelScrollHandler);
leftSide.addHandler(mouseWheelScrollHandler);
当在左侧滚动时,右侧移动到相同的垂直位置,然而,左侧再次移动(向下滚动),因此右侧似乎是滞后并且不能同时。它似乎左侧运行默认滚动鼠标滚轮事件。如何禁用它或其他方式使它们同时垂直滚动?谢谢你的帮助?
答案 0 :(得分:0)
我想我已经设法重现了你的问题。当我只在左侧面板上ScrollHandler
时,右侧面板滚动顺畅。但是当我有
左侧和右侧面板上的ScrollHandler
滚动滞后。
我带来的解决方案是仅当鼠标在左侧面板上时滚动右侧面板(反之亦然)。通过这种方法,两个面板都可以顺利滚动。
这是一个完整的示例代码:
public class ScrollTest {
private boolean mouseOverLeftPanel = false;
private boolean mouseOverRightPanel = false;
public ScrollTest() {
final ScrollPanel scrollPanelLeft = new ScrollPanel();
final ScrollPanel scrollPanelRight = new ScrollPanel();
scrollPanelLeft.setPixelSize(100, 150);
scrollPanelRight.setPixelSize(100, 150);
VerticalPanel highContentLeft = new VerticalPanel();
for(int i = 0; i < 20; i++)
highContentLeft.add(new Label("Label " + Integer.toString(i)));
VerticalPanel highContentRight = new VerticalPanel();
for(int i = 0; i < 20; i++)
highContentRight.add(new Label("Label " + Integer.toString(i)));
scrollPanelLeft.add(highContentLeft);
scrollPanelRight.add(highContentRight);
// scroll handlers
scrollPanelLeft.addScrollHandler(new ScrollHandler() {
@Override
public void onScroll(ScrollEvent event) {
if(mouseOverLeftPanel)
scrollPanelRight.setVerticalScrollPosition(scrollPanelLeft.getVerticalScrollPosition());
}
});
scrollPanelRight.addScrollHandler(new ScrollHandler() {
@Override
public void onScroll(ScrollEvent event) {
if(mouseOverRightPanel)
scrollPanelLeft.setVerticalScrollPosition(scrollPanelRight.getVerticalScrollPosition());
}
});
// mouse over handlers
scrollPanelLeft.addDomHandler(new MouseOverHandler() {
@Override
public void onMouseOver(MouseOverEvent event) {
mouseOverLeftPanel = true;
}
}, MouseOverEvent.getType());
scrollPanelRight.addDomHandler(new MouseOverHandler() {
@Override
public void onMouseOver(MouseOverEvent event) {
mouseOverRightPanel = true;
}
}, MouseOverEvent.getType());
// mouse out handlers
scrollPanelLeft.addDomHandler(new MouseOutHandler() {
@Override
public void onMouseOut(MouseOutEvent event) {
mouseOverLeftPanel = false;
}
}, MouseOutEvent.getType());
scrollPanelRight.addDomHandler(new MouseOutHandler() {
@Override
public void onMouseOut(MouseOutEvent event) {
mouseOverRightPanel = false;
}
}, MouseOutEvent.getType());
HorizontalPanel wrapper = new HorizontalPanel();
wrapper.add(scrollPanelLeft);
wrapper.add(scrollPanelRight);
RootPanel.get().add(wrapper);
}
}