we have a C++ application that hosts a flex application in a MFC dialog. Everything works fine, all button pushes etc are passed directly on to flex with no problem at all, except the enter and escape keys, which immediately closes the dialog.
We can trap the enter key, by implementing PreTranslateMessage() or OnOK()
and impede the window closing behavior, but we still have the problem of passing these enter key pushes on to the hosted flex app further.
There is no "default" button on the form or anything like that, perhaps MFC is linking the enter key to the close button in the title bar behind the scenes or something.
Does anyone have any ideas how we can stop MFC from treating the enter key from being a special case.
Thanks a lot for any hints.
Edit: Here is PreTranslateMessage() that mmonem requested.
BOOL CFlexDialog::PreTranslateMessage(MSG* pMsg)
{
if ((pMsg->message == WM_KEYDOWN))
{
if (pMsg->wParam == VK_RETURN)
{
m_ctrlFlex->OnReturnKeyPressed();
return TRUE;
}
}
return __super::PreTranslateMessage(pMsg);
}
But it is not a suitable solution, calling a method in the flex app like that, as it makes life too difficult for the flex developer, it means he must write a special version implementing the return key behavior for every control.
We just want MFC to treat the return and escape keys like every other key.
Remove OnOK() and OnCancel(); PreTransateMessage is enough after considering VK_ESCAPE.
Why don't you use:
m_ctrlFlex->SendMessage(WM_KEYDOWN, VK_RETURN, 0)
instead of
m_ctrlFlex->OnReturnKeyPressed();
in your implementation of PreTranslateMessage ?
MFC command buttons can respond to events even if they do not have the focus.
Have you tried trapping the OnClicked event and OnOk to return nothing?
Example: trap OnClick...
void CMyDialog::OnClickedMyOK()
{
CDialog::OnOK();
}
Then do a no-op in the OnOk()
void CMyDialog::OnOK()
{
}
This should stop the enter key from being processed.
Another approach is "Windows Subclassing." That is, sending messages from one Window Procedure, that is a WindProc() to another WndProc(). This may provide a way without direct intervention. (This is not C++ subclassing.)
Here's a way with MFC Subclassing Edit: Provided a better link.
Search for "Windows / MFC Subclassing" if more info needed.
The flex control/window has a WndProc and your window certainly has a WndProc, Windows Subclassing should work.
New Edit: Here is perhaps a better link for subclassing an ActiveX control.
ActiveX Controls: Subclassing a Windows Control
Subclassing Windows Forms Controls - More .Net-centric.
Notice: In MFC you should see these functions.
CWnd::SubclassDlgItem
CWnd::SubclassWindow
CDialog inherits from CWnd so you will see those two functions as "dialog" functions as well. They are key to making this work. If the flash window is a true window, use SubclassWindow. If it's a control use SubclassDlgItem.
And finally, if nothing else works. A product/library that will hopefully make it easy. EasyHook looks like a product here. EasyHook at CodeProject, you can get all the source code.
If you are having issues handling tabs & enter keys I would recommend you look into using a window instead of a dialog. The dialog adds modal ( if you are using modal ), tabbing & default button handling. If you don't need/want those features, or if they are getting in your way, then don't use a dialog.
If I understand what you are doing, then you want flex to handle tabbing, enter key, and all sorts of other messages. Get the dialog code out of the way. If you still want modal style, then you may have to handle the enable/disabling of parent windows - thats all that windows does when you open a modal dialog.
Related
My application consists of a WebView widget. A mouse click on the widget is not handled by the mousePressEvent() of my application, but by the WebView widget. So, I installed an event filter to receive the events. Now, I get notified of all events, except the mouseReleaseEvent for the right click (Everything works fine for left clicks and mousePressEvent for the right click is also getting registered). I guess it has got something to do with context events getting generated by right clicks (a pop-up menu gets generated). But since I am using a filter, the event should first be sent to me. The following is the code for the event filter
in Jambi, but I hope I can modify an answer given in Qt for Jambi.
public boolean eventFilter(QObject o,QEvent event)
{
if (event.type()==QEvent.Type.MouseButtonPress) // One can call the mousePressEvent() functions from here,which can do this work but speed
{
if (((QMouseEvent)event).button()==Qt.MouseButton.LeftButton)
{
mousebuttontype=1;
clickedorpressed=1;
}
else
if (((QMouseEvent)event).button()==Qt.MouseButton.RightButton)
{
mousebuttontype=2;
System.out.println("right");
}
t1=QTime.currentTime();
t1.start();
}
else
if (event.type()==QEvent.Type.MouseButtonRelease)
{
if (t1.elapsed()>900)
{
switch(mousebuttontype)
{
case 1: browser.back();
break;
case 2: browser.forward();
break;
}
}System.out.println("choda");
}
return false;
}
MY BASIC AIM IS GETTING THE TIME INTERVAL FOR WHICH THE RIGHT CLICK WAS PRESSED. ANY WORKAROUND ?
Some digging around certainly seems to suggest that there may be no right-mouse release event being generated if that is the trigger for a context menu on your particular system. These are conveyed as a QContextMenuEvent.
This Qt Labs post hints about this too.
A work around may be tricky if it is system dependent. Have you tried overriding event() in the QApplication class to see if the event comes through there? Some events don't necessarily get to the children but everything goes through QApplication::event().
Another option for you is, subclass Qwebview and override mouseReleaseEvent event
I've found a fix for this that I dont think will be system dependent.
My particular case was using mouseReleaseEvent in order to catch the events, and use them myself. I didn't get these events.
On all child widgets of the widget that I want to handle the event, I added to the class definition:
protected:
void mouseReleaseEvent(QMouseEvent *event) {event->ignore();}
This overrides the default implementation for context menu's, and sends the mouseReleaseEvent back up the parent chain like it would for other mousebuttons.
http://doc.qt.io/qt-5/qevent.html#ignore
This shows that it will probably propagate to the parent widget. As the link indicates, this fixed it for me at Qt 5.9, but I think it should work for virtually all version.
(I am aware this question is literally 7 years old, but it doesn't contain the fix that I think would be the best fix, and shows up as result 2 on google(qt not getting mouse release event on rightclick). So I think it deserves an up to date answer.)
Without going in to broader implementation explanations, the core problem I needed to solve related to this issue was that I needed to know if a context menu swallowed the right-click so I could ensure some custom state was handled properly. The simplest workaround I was able to find was to implement contextMenuEvent, which gets called after mousePressEvent, to detect if the event was accepted (a context menu was opened somewhere in my QGraphicsScene/Items). Here is a minimal example in Python to demonstrate how the event state might be used:
def contextMenuEvent(self, event):
event.setAccepted(False)
super(MyGraphicsView, self).contextMenuEvent(event)
self.__context_menu_used = event.isAccepted()
Note you can also skip running the the base class contextMenuEvent entirely to block the scene/items from opening a context menu. This is handy if you want to do 3D-DCC-like alt-RMB-zooming without accidentally opening a context menu, e.g.:
def contextMenuEvent(self, event):
# Block context menus if alt is held down
if event.modifiers() & QtCore.Qt.AltModifier:
return
event.setAccepted(False)
super(MyGraphicsView, self).contextMenuEvent(event)
self.__context_menu_used = event.isAccepted()
Scenario is : old site which has lots of JS code already written. If user want to change all the alert messages to new age jazzy Div based alert which are very common using JQuery, YUI, Prototype... etc.
There are mainly tree JS dialogs
1. alert
To changes this its simple we just have to write new function which will show the div popup and show the message, after that override the window.alert
function showDivAlert(strMessage){
//div popup logic and code
}
window.alert = showDivAlert;
2. prompt
This too look easy to write function to accept the string and show the text box for input value. Now as return action is based on the click of "OK" button life is easy here.
function shoDivPromp(strMessage){
//div pop up to show the text box and accept input from the user
}
window.prompt = shoDivPromp;
3. confirm
Now above two were easy to override and modify the default dialogs but there is complication with the confirm.
However default JS confirm dialog stops JS execution and when user click OK or Cancel execution is resumed by determining the return value (true/false). But if we user div popup the execution is not stopped which is problem. We can still implement the confirm but in that case we have to bind methods for OK and CANCEL case which will be attached to OK and CANCEL button. With this function signature will be like.
function newConfirm(msg, fun OkAction(), fun CancelAction)
Now this is problem that this cant help me change the confirm dialog across the site as we did with alert();
Question
I am not sure whether its possible or not to achieve but i think can be using some JS pattern. So let me know if its possible.
Now this is problem that this cant help me change the confirm dialog across the site as we did with alert();
That's correct. It's not possible to reproduce the synchronous nature of the alert/confirm/prompt functions in native JavaScript. There is the non-standard method showModalDialog which can do it using a separate pop-up document, but it's not supported by all browsers and it's generally considered highly undesirable.
So the plug-in-replacement strategy isn't going to work. You are going to have to change every place you called these methods in the rest of the script.
The usual pattern is to do it using inline anonymous functions, to preserve the local variables using a closure, eg. replace:
function buttonclick() {
var id= this.id;
if (confirm('Are you sure you want to frob '+id+'?'))
frob(id);
wipe(id);
}
with:
function buttonclick() {
var id= this.id;
myConfirm('Are you sure you want to frob '+id+'?', function(confirmed) {
if (confirmed)
frob(id);
wipe(id);
});
}
If you need this to be preserved you would need to look at a further nested closure or function.bind to do it. If you have your call to confirm in a loop things get considerably more difficult.
Obviously you also have to ensure that critical global state doesn't change whilst the confirm box is up. Usually this risk is minimised by greying out the rest of the page with an overlay to stop clicks getting through. However if you have timeouts they can still fire.
All 3 methods actually stop js execution, not just the confirm, because they're all modal dialogs. Personally, I would try to keep everything as asynchronous as possible as modal dialogs prevent interaction with the current document.
Your best bet is to use callback functions from the new confirm popup as you suggested yourself.
I'm having a hard time understanding exactly what you want to achieve. It sounds like you want to do something like the following:
Run some javascript code
Display a "confirm" box
Wait until the ok button or cancel button is clicked
Continue code when user clicks ok, return when user clicks cancel.
The reason you want to do this is that overriding the function with something that makes use of callbacks would require rewriting each section of code that uses the confirm function. If you want my advice, I would go ahead and rewrite the code so that it performs asynchronously. There's no way you can delay script execution without locking up the document which includes the OK and Cancel actions of your dialog.
if you changed the roles Alert / Prompt / Confirm. slows the execution pending user interaction to run the following code.
Overriding these functions, the code continues its execution.
To achieve this you have to modify each part of the code and work as if you were with asynchronous functions.
Then you can use any plugin for windows as sexy-alert-box, and overwrite Alert / Prompt / Confirm
The function signature would simply be:
function newConfirm(msg, okAction, cancelAction);
and would be used as:
function newConfirm(msg, okAction, cancelAction){
var ok = doWhateverPromptIsNecessary();
if (ok) {
okAction();
} else {
cancelAction();
}
}
That is, to pass function "pointers" in to a function as arguments, simply pass in the function name without the (). The function signature is the same.
Is there a way to make a Perl/Tk window's close ('X') button disabled?
I know how to ignore clicking it using the technique described here, but I would much rather have it disabled.
I'm using Perl/Tk on Windows.
Thanks,
splintor
If you are in a Unix environment you are out of luck. The "close" button is managed by the Window Manager of the desktop which is a completely different process that you have no control on.
Even if by a hack you disable the "close" button the user can always bring it back
if the window manager permits this. The enlightenment window manager for example can
enable/disable all window buttons on demand.
The technique you give in the link is doing exactly this. It does not remove
the "close" button. It just gives a hint to the window manager (WM_DELETE_WINDOW).
It is up to the window manager if this hint will be honoured or not.
See also the icccm and NetWM pages.
What you want might be possible on Windows, but my experience with this OS
is limited so perhaps another poster will know this.
I have an app that I wrote, i was wondering about the same thing, and i don't disableit, but i have a call back to a subroutine, that simply does return;
$Mw->protocol('WM_DELETE_WINDOW',sub{return;});
According to the Perl Monks, it looks like the following works on Windows:
#!/usr/bin/perl
use warnings;
use strict;
use Tk;
my $window = new MainWindow;
$window ->title("Close test");
$window ->geometry("400x250");
#prevents window from closing
$window->protocol('WM_DELETE_WINDOW' => sub {
print "Do stuff before exiting\n";
exit;
});
MainLoop;
In the above code, you are intercepting the signal sent when the user presses 'X' and can then write your own subroutine to execute when the button is pressed.
If you want to disable the close icon, set sub to empty (effectively telling it to "do nothing when pressed"): 'WM_DELETE_WINDOW' => sub {}
If you don't manage to really disable the close button (I mean to grey it out or even remove it from the window decoration), it might be the most intuitive thing to iconify your window instead of closing it. This is what I did.
$window->protocol('WM_DELETE_WINDOW', sub { $window->iconify(); } );
I may be missing something here because I thought this might be really easy but...
Using Flex, how can you tell when a ComboBox is open? I do find the open and close events that this component dispatches can be flaky so I'm looking for something a little more solid - it's probably staring me in the face.
How about checking either the existence or the visibility of the dropDown component?
The dropDown is a component of type ListBase, and can be accessed through the dropDown property. So maybe something like this (I didn't have time to test this myself):
if (myComboBox.dropDown != null && myComboBox.dropDown.visible) {
// myComboBox is open
}
The myComboBox.dropDown != null is a safety check so you will not get runtime errors trying to access the visible property of a null object.
The designers probably thought it was enough with the open and close events.
EDIT: I'll clarify that. Looking for a property that would reveal the opened/closed status of the combobox I fail to find it. And to my experience there's nothing flaky about the event system.
I am writing an intranet application and am considering the use of a pop up window. I am not worried about accessibility since it's an intranet app.
The scenario is such as I need to be able to have the same code be used in a server page as well as in the middle of a process; which is why I decided when using it in the middle of the process, it's best to have it as a pop up window to running out of the real estate on the screen.
Any thoughts on this? I am hesitant to use a pop up window in such a manner as I usually only use it for error messages.
I don't completely understand what you're trying to do, but I think a popup window might be somewhat of an issue if the user's browser automatically blocks popup windows. Plus, if you were trying to run a process in the popup window, the user could close it and no longer have a way to check on the process.
Would it be possible to use Ajax to call back to a web service that gives the page information about the process? You could give the user a way to make the Ajax call to check on the status of the process or just have it continually polling in the background.
Edit:
You said you weren't too familiar with Ajax. For the most part, there are libraries to handle all the of hard details. I'll recommend jQuery because that's what I've been using for a while now.
If you go the Ajax route you'll be able to contain everything on one page and make the updates you need to make when the Ajax call is successful. Depending on how you write the code, it should be pretty reusable if you do it right. It really depends on how specific the your needs on each page.
Take a look at the jQuery documentation though. It may have what you need already built into it. Otherwise, someone else might be able to suggest some reasons why their favorite JavaScript library works better for what you're trying to do.
I think you might want to do something like this:
Inside of the parent page:
<input id="btnShowModal" runat="server" type="button" value='Show Modal' onclick="ShowModal()" />
function ShowModal()
{
var retVal = window.showModalDialog("MyPopup.aspx?param1=value","","center=yes;dialogWidth=200px;dialogHeight=200px;status:0;help:0")
if(retVal != "" && retVal != undefined)
{
//This code will be executed when the modal popup is closed, retVal will contain the value assigned to window.returnValue
}
}
Inside of the modal popup:
<input id="btnSave" runat="server" type="button" value='Save' onclick="Save()" />
function Save()
{
window.returnValue = "Whatever you want returned to the parent here"
window.close()
}
The usual argument against popup windows is that they are unreliable. The user may have disabled script initiated popups, I know I have.
In a controlled environment, such as an inranet, you may be able to be guaranteed that this is not the case, but even so, why risk it, there is an alternative.
Instead of popping up a new window just insert a new, absolutely positioned <div> into the document and insert your content into that using ajax or even an <iframe>. There are lots of examples/libraries on the web.
Thickbox for jQuery for example. There are of course scripts that don't require libraries.
I generally use a div with a z-index and absolute positioning; the .show() can be written and called on demand, it would have a button to .close(), and AJAX can make it seem modal so it must be clicked to close if you so desire. Then again, I hate messageboxes.
I was trying to avoid AJAX, simply because I have never used and don't have the time frame to learn it now. However, I am not totally opposed to it.
In short what I need to do is for the pop up window interact back with the page. Imagine that on the page I am building the links of the chain. Each link has unique properties. When user clicks on "ADD LINK" button, I was thinking have a pop up window with the little form and a Save button. The only issue with this is that a pop up needs to interact with the page; we need to know when something has been saved or not saved.
A div on the same page is one way. A pop up is yet another way. Another catch is that this code (adding new link) needs to be reusable, because I am also going to have a page that just creates new links.