GWT 2.5.1; using Eclipse 4.2 with GPE;
UI specified with UiBinder
The app puts up a splash screen containing a "Go" button. That button's click handler does various initialization, including hiding itself and showing three other buttons, images, and text; it also initiates a server request (XMLHttpRequest) via a RequestBuilder. The RequestBuilder callback uses the returned server data to draw a bar graph in a canvas element.
After I click the "Go" button the browser window looks as expected with all the visual elements mentioned above. But the three buttons are not responsive to clicks. Not only are their handlers not invoked, they don't show the slight visual indication of activation when the mouse is clicked on them. The browser is not frozen; e.g., if the window is resized the app's resize handler is called.
Based on logging: after the "Go" button handler returns the RequestBuilder callback executes; then "nothing happens" i.e., there are no more log outputs (unless I resize the window).
FWIW this is my first GWT endeavor.
By experiment, I found a partial answer. The three non-responsive buttons are declared in the ui.xml file with {style.hidden} referring to a visibility:hidden attribute in my .css. In the java code I unhide these buttons with:
protected void showElement(Element e) {
e.removeClassName(style.hidden());
}
Evidently starting life as hidden and then shown this way is insufficient to activate the buttons. I am about to go off to research why this is so, but an answer to this "smaller" question is still welcome as long as I've not posted a comment indicating that I am less ignorant.
(too long for a comment)
I have just discovered that the problem relates to the fact that I have buttons in the same position, of which only certain ones are supposed to be visible at a given time. In other words, the user would see at the same position on the page one of:
ButtonA ButtonB ButtonC
or
ButtonD ButtonE ButtonF
or
BigButtonG (as wide either of the preceding groups)
The problem is that regardless of visibility, whichever of the three above displays is declared last has (in effect) a higher z-index and is the only one that will be mouse-responsive. So I am just about to implement a solution of explicitly setting div z-indexes in the code which shows/hides button groups.
Can you set the button's positions in your UiBinder file rather than in your Java code? Place them in a HorizontalPanel and they'll be spaced automatically.
And rather than interacting at the Element level to hide a button, instead call your button instance with setVisible(true); e.g., buttonA.setVisible(true)
Related
I have a main form...imagine that...that for most of my users will be the only form they use. Naturally, it contains tabs with sub forms.
I have a navigation sub form on the left side of this form that changes based on the user's rights level. Currently, this sub form is all buttons...and 1 always is selected as the default tab stop for that form.
I don't want to highlight any of them at first...and I can remove the highlight by switching off Tab Stops for all buttons. However, I'm not sure that I want to remove that functionality all together...and it still highlights a button. I'd just like for there to not be a default button highlighted.
As you can see, Add Course is 'selected'. I can't seem to find the correct terminology to search for a way to do this. I tried using a smaller button set behind another button, but since it has the focus, it moves to the front. Using a text field with the same colors as the background shows the cursor in a random, blank area...not visually ideal.
I'm sure that there is someone here clever enough to have this figured out. Please enlighten me. I don't care if this can be handled in VBA code or through design view.
"Focus" is the word you're looking for - you don't want any visible control to have the focus when opening the form.
The easiest method is an invisible button: create a button with Transparent = True, and an empty OnClick (i.e. the button does nothing, even when accidentally clicked).
Move this button to the top in the Tab Order, so it has the focus when opening the form.
But if your users use TAB to walk through the buttons, there will be one position where the focus disappears (when circling around from the last to first control). I don't know if it will confuse them.
Create a button on the main form itself.
Named is cmdDummyButton with the following GotFocus event code.
Set the tab order property to 0 (ie first)
Make the button transparent.
This will cause no control on the form to have the focus when it starts up.
Private Sub cmdDummyButton_GotFocus()
Static IveHadFocusAlready As Boolean
If Not IveHadFocusAlready Then
Me.cmdDummyButton.Enabled = False
IveHadFocusAlready = True
End If
End Sub
Sweet.
I'm trying to build a Wizard framework in Windows Forms. I've managed to glean a lot of useful tips from this and other sites which have gotten me very close to success. However, I'm having a problem with displaying an ErrorProvider on any tab page other than the first page of the wizard.
My Wizard control is a UserControl. It contains a custom tab control that I've derived from TabControl so that I can hide tabs and ignore attempts to navigate between tabs using keypresses, along with the usual collection of Back/Next/Finish/Cancel buttons at the bottom of the control.
I've used reflection to allow me to raise the validation events on a particular TabPage that belongs to the Wizard Control when I hit the Next button. (I don't want to validate the whole TabControl, only the currently active page.) When I do this, I see in the debugger that my Validating routine for the controls on the current tab page is correctly called and I see that I've called the ErrorProvider that I've attached to the particular control (a TextBox in this case) with a valid error message. I set Cancel to true for the CancelEventArgs in the validating routine and that's picked up by the code that uses the reflection mechanism so that I see that I've failed and don't change tabs. And I set the focus successfully to the control that failed validation.
So all that appears to be working just fine.
Unfortunately, I don't see the ErrorProvider's cheery blinking icon unless I'm on the first tab page. For all of the other tab pages, there's no message visible at all.
I'm baffled. Any thoughts? I can provide code snippets, if helpful.
Thanks!
I assume that in your case the button that moves to the next step of the wizard is placed outside (below) the TabControl
I noticed that the icon is displayed correctly if I pressed the button without releasing the mouse button. It seems that the button outside the container gets focused event though a validation error has occurred (normally you would not be able to leave the active control).
I worked around this issue by registering an event handler for the buttons MouseUp event to "refocus" the TabControl:
private void cmdOK_MouseUp(object sender, MouseEventArgs e)
{
tabControl1.Focus();
}
Note: you also need to set your forms ActiveControl property the one of the controls that failed validation.
I have a header bar at the top of the page which contains buttons and anchors. One of the anchors on the header bar opens a dialog doing the following:
The view calls the activity which does a goTo to a new place, in the start method of the activity which is associated with this place, is a call to instantiate a custom dialog box.
Now there are two problems which are occurring here:
1) Because the place is being navigated to from the header bar, the header bar activity is being shut down by the activity manager so the buttons do not work after clicking the anchor. I do not want the header bar activity to be shut down.
2) Upon clicking this anchor, my main panel in the centre of the screen becomes blank. I have no idea why this is happening but obviously dont want it to.
How to fix these two issues?
I do not want the header bar activity to be shut down.
Have a look at David Chandler's Google I/O 2011 GWT session. It touches on the type of master/details architecture you're describing. I highly recommend it in general and for this question specifically the part following the 18th minute, when David begins a thorough overview of Activities and Places.
Just as suggested in the presentation, you might choose changes to your header bar to happen in reaction to PlaceChangeEvents only, without there being a full-fledged header bar activity.
I'm working something like a dynamic menu, where you click some radio buttons and it shows a specific form, each radio control matches to a different form.
Examples from the showcase always base themselves on the Tabs widget and I don't need that behaviour.
I opted for placing all the forms inside one Canvas and hide/show them accordingly (Not sure this was the best idea, if someone knows better I would like to hear it)
Now my problem is that every onClick event has to .show() one form and .hide() the other 9. that is annoying.
Is there a way to "get" the current displayed child in the Canvas and hide it?
If what you want is basically mutex display, you could put all the components as members of a Layout instead of a Canvas, then use setVisibleMember(). That hides all other members.
I have a menu drop down action in the coolbar. It has 3 sub items that form a radio group. I would like to change the icon shown in the coolbar when the user selects one of these options.
I've googled and seen that I should look at:
org.eclipse.ui.commands.ICommandService.refreshElements(String, Map)
and
org.eclipse.ui.commands.IElementUpdater
Its probably the right thing to look at exception its not enough information. One or two small code snippets will be excellent.
Thanks in advance.
Ok basically if you don't want to use a "custom" control the what to do it is to have your handler (handler that is linked to the specific command) implement IElementUpdater. When every the toolbar item gets shown or clicked on (i.e if the user selects on the the radio buttons) the method: updateElement(UIElement element, Map parameters) gets called.
The element has a setIcon() method and this is what i used to change the icon of the menu drop down action.
Every update to the Coolbar points to the specialization of the WorkbenchWindowControlContribution class.
This bug 186800 has some code example in it which can be of interest.