for my project I need to function my menu-bar like windows start button.
How can i achieve this in GWT?
What i tried up to now is:
public class MyMenuBar extends Composite implements MouseDownHandler{
#Override
public void onMouseDown(MouseDownEvent event) {
System.out.println("IMAGE CHANGED, using new safe html");
}
MenuBar myMenu;
public MyMenuBar(){
myMenu = new MenuBar();
myMenu.addItem(safeHtmlOfImage, popupMenuBar);
this.addDomHandler(this, MouseDownEvent.getType());
initWidget(myMenu);
}
}
Issue is never onMouseDown(MouseDownEvent event) is invoked.
Please help me, how can i achieve this. I am losing my second day with this thing.
Tell me what ever you thinks about it...
I kind of solved issue, but nit think this is the actual solution: by setting the style code for the Menubar.
.gwt-MenuItem
{
background-image: url("img/navigatorDeActive.png");
}
.gwt-MenuItem-selected
{
background-image: url("img/navigatorActive.png");
}
Related
after hours of searching and trying, I decided to ask here.
JqmHeader.java
public class JqmHeader extends ComplexPanel {
public JqmHeader() {
setElement(DOM.createDiv());
getElement().setAttribute("data-role", "header");
}
public void add(Widget widget) {
super.add(widget, getElement());
}
}
JqmPage.java
public class JqmPage extends ComplexPanel {
...
public JqmPage(String id) {
setElement(Document.get().createDivElement());
getElement().setAttribute("data-role", "page");
getElement().setAttribute("data-url", id);
RootPanel.get().add(page);
render(page.getId());
}
private native void render(String id) /*-{
$wnd.$("#" + id).page();
}-*/;
...
}
MyPage.java extends JqmPage.java
...
JqmHeader header = new JqmHeader();
Button b = new Button("TestButton");
b.addClickHandler(new ClickHandler() {
#Override
public void onClick(ClickEvent event) {
Window.alert("TestButton clicked");
}
});
header.add(b);
this.add(header);
...
My Problem
So, my Problem is, that the ClickHandler from the Button in the header bar doesn't fire. If I add the Button not to the header, but to the "RootPage", like
this.add(b)
, everything works.
I think it must lie at the jquery-mobile header implementation. Are there any workarounds /ideas?
Thanks from Berlin,
Alex
JQuery Mobile swallows the events on headers so they are not propagated to GWT. What I did in solving this for jqm4gwt (https://github.com/sksamuel/jqm4gwt) was to have a general listener on the page level and then compare event source. If it was a button in the header then I fire that event on the button manually.
Take a look at bindHeaderEvents in https://github.com/sksamuel/jqm4gwt/blob/master/src/main/java/com/sksamuel/jqm4gwt/JQMPage.java
Also, the jqm4gwt project might be a good solution for you to save you having to invent all these widgets yourself.
If you want to take a look at a pure GWT solution for building mobile apps you could take a look at http://www.m-gwt.com
How can I auto scroll the GWT SuggestBox with max-height set on the PopupPanel holding the SuggestBox? Currently when the user presses keyboard up keys and down keys styles changes on the suggested items and pressing enter will select the currently selected item on the list.
When the item is located in lower than the max-height scroll bars doesn't scroll.
I tried extending the SuggestBox and inner class DefaultSuggestionDisplay to override moveSelectionDown() and moveSelectionUp() to explicitly call popup.setScrollTop().
In order to do this I need access to the absolute top of the currently selected MenuItem therefore need access to SuggestionMenu which is also an inner class of SuggestBox which is private and declared as a private member within DefaultSuggestionDisplay without getter. Since GWT is a JavaScript we can't use reflection to access it.... Does anyone have a workaround for this issue?
Thanks.
I've been searching around and couldn't find a proper solution (apart from reimplementing SuggestBox). The following avoids reimplementing SuggestBox:
private static class ScrollableDefaultSuggestionDisplay extends SuggestBox.DefaultSuggestionDisplay {
private Widget suggestionMenu;
#Override
protected Widget decorateSuggestionList(Widget suggestionList) {
suggestionMenu = suggestionList;
return suggestionList;
}
#Override
protected void moveSelectionDown() {
super.moveSelectionDown();
scrollSelectedItemIntoView();
}
#Override
protected void moveSelectionUp() {
super.moveSelectionUp();
scrollSelectedItemIntoView();
}
private void scrollSelectedItemIntoView() {
// DIV TABLE TBODY TR's
NodeList<Node> trList = suggestionMenu.getElement().getChild(1).getChild(0).getChildNodes();
for (int trIndex = 0; trIndex < trList.getLength(); ++trIndex) {
Element trElement = (Element)trList.getItem(trIndex);
if (((Element)trElement.getChild(0)).getClassName().contains("selected")) {
trElement.scrollIntoView();
break;
}
}
}
}
Following this discussion on Google groups, I implemented a similar solution which is a bit more concise due to the use of JSNI:
private class ScrollableDefaultSuggestionDisplay extends DefaultSuggestionDisplay {
#Override
protected void moveSelectionDown() {
super.moveSelectionDown();
scrollSelectedItemIntoView();
}
#Override
protected void moveSelectionUp() {
super.moveSelectionUp();
scrollSelectedItemIntoView();
}
private void scrollSelectedItemIntoView() {
getSelectedMenuItem().getElement().scrollIntoView();
}
private native MenuItem getSelectedMenuItem() /*-{
var menu = this.#com.google.gwt.user.client.ui.SuggestBox.DefaultSuggestionDisplay::suggestionMenu;
return menu.#com.google.gwt.user.client.ui.MenuBar::selectedItem;
}-*/;
}
Ok, I finally found the solution. I had to create my own suggest box based on GWT SuggestBox implementations. But follow below in custom implementaion:
-Place ScrollPanel to PopupPanel then place MenuBar to ScrollPanel
-In moveSelectionUp() and moveSelectionDown() of your new internal SuggestionDisplat implementation add the code below:
panel.ensureVisible( menu.getSelectedItem( ) );
This is not achievable by extending the SuggestBox since we won't have access to selected
MenuItem unless overriding protected getSelectionItem() method as public method.
Finally add CSS:
max-height: 250px;
To the popupPanel in your display implementations.
I am currently developing a paint-like application for GWT. I would like to add a mouse handler that runs when the user drags the mouse across the canvas(like making a square,etc;), the problem is that I'm not surewhat handler to use. Looking through the handlers implemented in canvas has lead me to some hints, but the documentation as to what event the apply to is scant.
Does anyone know how I should implement it? Thanks.
There is no "dragging" handler. You imlement "dragging" with MouseDown, MouseMove and MouseUp events.
class YourWidget extends Composite
{
#UiField
Canvas yourCanvas;
private boolean dragging;
private HandlerRegistration mouseMove;
#UiHandler("yourCanvas")
void onMouseDown(MouseDownEvent e) {
dragging = true;
// do other stuff related to starting of "dragging"
mouseMove = yourCanvas.addMouseMoveHandler(new MouseMoveHandler(){
public void onMouseMove(MouseMoveEvent e) {
// ...do stuff that you need when "dragging"
}
});
}
#UiHandler("yourCanvas")
void onMouseUp(MouseUpEvent e) {
if (dragging){
// do other stuff related to stopping of "dragging"
dragging = false;
mouseMove.remove(); // in earlier versions of GWT
//mouseMove.removeHandler(); //in later versions of GWT
}
}
}
I've messed around with this as well and produced this little thing awhile ago:
http://alpha2.colorboxthing.appspot.com/#/
I basically wrapped whatever I needed with a FocusPanel. In my case it was a FlowPanel.
From that program in my UiBinder:
<g:FocusPanel ui:field="boxFocus" styleName="{style.boxFocus}">
<g:FlowPanel ui:field="boxPanel" styleName="{style.boxFocus}"></g:FlowPanel>
</g:FocusPanel>
How I use the focus panel (display.getBoxFocus() seen below just gets the FocusPanel above):
display.getBoxFocus().addClickHandler(new ClickHandler() {
#Override
public void onClick(ClickEvent event) {
}
});
display.getBoxFocus().addMouseDownHandler(new MouseDownHandler() {
#Override
public void onMouseDown(MouseDownEvent event) {
}
});
display.getBoxFocus().addMouseMoveHandler(new MouseMoveHandler() {
#Override
public void onMouseMove(MouseMoveEvent event) {
}
});
display.getBoxFocus().addMouseUpHandler(new MouseUpHandler() {
#Override
public void onMouseUp(MouseUpEvent event) {
}
});
// etc!
To answer your question about what handler to use for "dragging" I haven't found a single handler to do that for me. Instead I used a MouseDownHandler, MouseMoveHandler, and a MouseUpHandler.
Use the MouseDownHandler to set a flag that determines when the users mouse is down. I do this so that when MouseMoveHandler is called it knows if it should do anything or not. Finally use MouseUpHandler to toggle that flag if the user has the mouse down or not.
There have been some flaws with this method (if the user drags their mouse off of the FocusPanel), but because my application was just a fun side project I haven't concerned myself with it too much. Add in other handlers to fix that if it becomes a big issue.
This should not be causing me so much pain but it is. It is a very weird problem. In a GWT application, I have two .java files, login.java and application.java.
In login.java, I'm creating a user login page where if the username and password is verified the user is logged into the application and application.java takes from here.
Now in application. java's onModuleLoad() this is how i'm starting with a login page.
public void onModuleLoad() {
Login login = new Login();
login.textBoxUsername.setFocus(true);
RootLayoutPanel.get().add(login);}
This works great, except for the tiny problem of not being able to set focus on the username TextBox when the page loads. I have tried evrything I can think of. But the focus just doesn't get set on the TextBox. If anyone can suggest a solution, please do. Your help is greatly appreciated.
Solution: (In case it helps anyone facing the same issue)
final Login login = new Login();
Scheduler.get().scheduleDeferred(new ScheduledCommand() {
public void execute () {
login.textBoxUsername.setFocus(true);
}
});
RootLayoutPanel.get().add(login);
Try using Scheduler.scheduleDeferred():
public void onModuleLoad() {
Login login = new Login();
Scheduler.get().scheduleDeferred(new Scheduler.ScheduledCommand () {
public void execute () {
login.textBoxUsername.setFocus(true);
}
});
RootLayoutPanel.get().add(login);
}
Update: answer updated to use Scheduler.get().scheduleDeferred() instead of DeferredCommand, which is deprecated.
Why using DefferedCommand, I think it's better to use someWidget.getElement().focus() which is a native Javascript. I'm using it everywhere, I've not seen any problem.
If your Widget extends Composite, you can:
#Override
protected void onAttach() {
super.onAttach();
textBoxUsername.setFocus(true);
}
It would be so easy for GWT to store a 'wantsFocus' in the internal state, and call focus after the widget is attached. We are still waiting after many years for that feature however...
Still, even after the attach handler is called, setFocus does not always work.
So in the meantime, our GwtUtil library has used the following code. It is a combination of several other solutions, and has been wrapped in a utility function:
static public void setFocus(final FocusWidget focusWidget) {
if (focusWidget.isAttached()) {
Scheduler.get().scheduleDeferred(new Scheduler.ScheduledCommand() {
#Override
public void execute() {
focusWidget.setFocus(true);
}
});
} else {
focusWidget.addAttachHandler(new AttachEvent.Handler() {
#Override
public void onAttachOrDetach(AttachEvent event) {
if (event.isAttached()) {
Scheduler.get().scheduleDeferred(new Scheduler.ScheduledCommand() {
#Override
public void execute() {
focusWidget.setFocus(true);
}
});
}
}
});
}
}
And call it like this:
setFocus(myTextBox);
It makes sense to use a utility function; If and when GWT finally makes setFocus work, you won't have to change your source code in multiple places.
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.)