I'm having trouble getting ScrollPanel.scrollToBottom to work. It's not scrolling to the bottom of the panel. Here's an example snippet:
FlexTable flexTable = new FlexTable();
// Add loads of rows to the flex table here..
ScrollPanel scrollPanel = new ScrollPanel(flexTable);
scrollPanel.scrollToBottom();
// Add the scrollPanel to the view here..
I have also tried using scrollToBottom() method in the onLoad() overriden method, but it doesn't work.
What am I doing wrong here?
Delay the scrollToBottom() command, so that the ScrollPanel is ready to take input.
Scheduler.get().scheduleDeferred(new Scheduler.ScheduledCommand() {
#Override
public void execute() {
// your commands here
scrollPanel.scrollToBottom();
}
});
Related
I am performing the following action in GWT
public class FooPanel extends SimplePanel {
private String url;
public FooPanel () {
super(DOM.createAnchor());
Button button = new Button();
button.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
foo();
}
});
add(button);
}
}
however when I run the code I get the following error
SimplePanel can only contain one child widget
However Button is a single widget so I am not sure what the problem is? The problem doesn't occur if i don't add the button
Remove this line:
super(DOM.createAnchor());
You don't need it.
You can simply use your Button in your code, or extend a Button widget. Adding a Button to a SimplePanel does not offer any benefits.
Have a look at source code of SimplePanel#add() to analyze this error.
#Override
public void add(Widget w) {
// Can't add() more than one widget to a SimplePanel.
if (getWidget() != null) {
throw new IllegalStateException("SimplePanel can only contain one child widget");
}
setWidget(w);
}
Now its clear from the source code that you have already added a widget in SimplePanel.
Call SimplePanel#getWidget() to get the already added widget.
Look at the source code of default constructor if SimplePanel class. It might help you to understand that how SimplePanel enclose the widget inside it.
/**
* Creates an empty panel that uses a DIV for its contents.
*/
public SimplePanel() {
this(DOM.createDiv());
}
Try with setWidget(button); instead of add(button);
I have a ScrollPanel and I want to reset his scrolling position when it is hidden.
To do so I call the scrollTop method. As I can see it is not working when the ScrollPanel is hidden.
Here a sample code:
public void onModuleLoad() {
StringBuilder html = new StringBuilder();
for (int i = 0; i<1000; i++) html.append("row "+i+"<br>");
HTMLPanel content = new HTMLPanel(html.toString());
final ScrollPanel scrollPanel = new ScrollPanel(content);
scrollPanel.setHeight("200px");
RootPanel.get().add(scrollPanel);
RootPanel.get().add(new Button("TEST", new ClickHandler() {
#Override
public void onClick(ClickEvent event) {
scrollPanel.scrollToTop();
scrollPanel.setVisible(false);
scrollPanel.scrollToBottom();
scrollPanel.setVisible(true);
}
}));
}
After clicking the TEST button the ScrollPanel keep is top position.
Any idea how to scroll it when hidden?
You can't scroll a hidden element because it does not have an offset position, i.e. both "top" and "bottom" would return zero.
See a possible solution: http://blog.gaijindesign.com/jquery-scrolltop-to-a-hidden-element/
I'm trying to add new widgets on an RPC view by clicking on an existing button. The code that I'm using is the following:
public void createPartControl(final Composite parent) {
parent.setLayout(new RowLayout(SWT.HORIZONTAL));
Button btnNewButton = new Button(parent, SWT.NONE);
btnNewButton.setText("New Button");
btnNewButton.addMouseListener(new MouseAdapter() {
#Override
public void mouseDown(MouseEvent e) {
Button b=new Button(parent,SWT.BUTTON1);
b.setText("asdasd");
}
});
}
The buttons are getting added on the view but are not visible. If I resize the view then they become visible. Why is this happening and how can it be solved?
I need somehow to refresh the view or call the event that the resize action calls.
The attached code works without problems in standard java applications.
Thank you,
Nick
Call the layout method of your parent Composite when you add a widget:
btnNewButton.addMouseListener(new MouseAdapter() {
#Override
public void mouseDown(MouseEvent e) {
Button b=new Button(parent,SWT.BUTTON1);
b.setText("asdasd");
parent.layout();
}
});
I'm new to GWT programming. So far I have a DialogBox which is supposed to collect a login and a password, which can if required launch another DialogBox that allows someone to create a new account.
The first of these two DialogBoxes always appears at the top left of the browser screen, and can't be dragged, although part of the definition of a DialogBox is that it can be dragged. However, the second DialogBox can be dragged about the screen without any problem.
What I'd really like is for the first DialogBox to appear in the middle of the screen & be draggable, both of which I thought would happen automatically, but there's not.
So, what things can stop a DialogBox from being draggable? There is nothing on the RootPanel yet. Does that make a difference?
Code fragments available if they help, but perhaps this general outline is enough for some pointers.
Thanks
Neil
Use dialogBox.center() This will center your DialogBox in the middle of the screen. Normally a DialogBox is by default draggable.
Just tried it out and it doens't matter if your RootPanel is empty our not. When I just show the DialogBox on ModuleLoad it is draggable and it is centered. Probably the problem is situated somewhere else.
This is the example of google itself:
public class DialogBoxExample implements EntryPoint, ClickListener {
private static class MyDialog extends DialogBox {
public MyDialog() {
// Set the dialog box's caption.
setText("My First Dialog");
// DialogBox is a SimplePanel, so you have to set its widget property to
// whatever you want its contents to be.
Button ok = new Button("OK");
ok.addClickListener(new ClickListener() {
public void onClick(Widget sender) {
MyDialog.this.hide();
}
});
setWidget(ok);
}
}
public void onModuleLoad() {
Button b = new Button("Click me");
b.addClickListener(this);
RootPanel.get().add(b);
}
public void onClick(Widget sender) {
// Instantiate the dialog box and show it.
new MyDialog().show();
}
}
Here more information about the DialogBox.
Without seeing any of your code it's hard to tell what's going wrong. The following code works for me (ignore the missing styling...):
public void onModuleLoad() {
FlowPanel login = new FlowPanel();
Button create = new Button("create");
login.add(new TextBox());
login.add(new TextBox());
login.add(create);
create.addClickHandler(new ClickHandler() {
#Override
public void onClick(ClickEvent event) {
final DialogBox box = new DialogBox();
FlowPanel panel = new FlowPanel();
Button close = new Button("close");
close.addClickHandler(new ClickHandler() {
#Override
public void onClick(ClickEvent event) {
box.hide();
}
});
panel.add(new Label("some content"));
panel.add(close);
box.setWidget(panel);
box.center();
}
});
DialogBox firstBox = new DialogBox(false, true);
firstBox.setWidget(login);
firstBox.center();
}
Both boxes are draggable and shown in the center of your browser window.
Looks like you're overriding this method in Widget:
public void fireEvent(GwtEvent<?> event) {
if (handlerManager != null) {
handlerManager.fireEvent(event);
}
}
In Widget, handlerManager refers to a private HandlerManager.
Either add super.fireEvent(event) to your method or as you have done rename it.
Well, with vast amounts of trial and error I have found the problem, which was just this: I had a method in an object I'd based on DialogBox called fireEvent, which looked like this:
public void fireEvent(GwtEvent<?> event)
{
handlerManager.fireEvent(event);
}
Then, when a button was clicked on the DialogBox, an event would be created and sent off to the handlerManager to be fired properly.
And it turns out that if I change it to this (LoginEvent is a custom-built event):
public void fireEvent(LoginEvent event)
{
handlerManager.fireEvent(event);
}
... or to this ....
public void fireAnEvent(GwtEvent<?> event)
{
handlerManager.fireEvent(event);
}
the DialogBox is draggable. However, if the method begins with the line
public void fireEvent(GwtEvent<?> event)
then the result is a DialogBox which can't be dragged.
I'm a bit unsettled by this, because I can't fathom a reason why my choice of name of a method should affect the draggability of a DialogBox, or why using a base class (GwtEvent) instead of a custom class that extends it should affect the draggability. And I suspect there are dozens of similar pitfalls for a naive novice like me.
(Expecting the DialogBox to centre itself was simply my mistake.)
I am trying to focus on a particular list view in a tree, I am using the following code
this.txtListName.setCursorPos(this.txtListName.getText().length());
this.txtListName.setFocus(true);
The text view has the cursor blinking inside it but when I type a key nothing happens, I have to select the text view again before being able to type.
Why is this happening.
SOLVED
The setting the the focus was done inside a for loop that looped over and created the Tree Items, when I removed it from the for loop it worked.
Could it be that something in your current call stack is taking the focus away after you set it. You could try setting the focus in a timeout:
(new Timer() {
#Override
public void run() {
txtListName.setFocus(true);
}
}).schedule(0);
I've tried to recreate your problem but the following snippet works for me:
public void onModuleLoad() {
Tree tree = new Tree();
final TextBox box = new TextBox();
box.setText("some content");
tree.add(box);
Button btn = new Button("set focus");
btn.addClickHandler(new ClickHandler() {
#Override
public void onClick(ClickEvent event) {
box.setCursorPos(box.getText().length());
box.setFocus(true);
}
});
RootPanel.get().add(tree);
RootPanel.get().add(btn);
}
Isn't that what you're trying to achieve?