What does GTK_WINDOW(window)->allow_shrink = TRUE mean in c? - c

I'm just getting started with gtk,anyone knows what this means?
GTK_WINDOW(window)->allow_shrink = TRUE;

It means the user can resize the window to smaller dimensions than were specified on creation of the window. GTK+ has an excellent reference, a quick search is all you need.

According to the GTK docs, something you shouldn't do:
If allow_shrink is TRUE, the user can
shrink the window so that its children
do not receive their full size
request; this is basically a bad
thing, because most widgets will look
wrong if this happens. Furthermore
GTK+ has a tendency to re-expand the
window if size is recalculated for any
reason. The upshot is that
allow_shrink should always be set to
FALSE.
See this page for more info.

If TRUE, the window has no mimimum size. Setting this to TRUE is 99% of the time a bad idea.
Default value: FALSE
If allow_shrink is TRUE, the user can shrink the window so that its children do not receive their full size request; this is basically a bad thing, because most widgets will look wrong if this happens. Furthermore GTK+ has a tendency to re-expand the window if size is recalculated for any reason. The upshot is that allow_shrink should always be set to FALSE.

If you are referring to the GTK_WINDOW(window) part, then I imagine it is casting/adjusting the pointer to obtain a pointer to a struct type for a window object that contains a variable called allow_shrink.

Related

Coded UI - How do we find if something exists when IsVisible, Exists, TryGetClickablePoint etc all return true when I can't see the control?

I am testing a WPF application and am not privy to it's exact workings but I am finding many instances where I need to find if a control is shown. All the traditional answers on this on Stack Overflow and MS forums etc say to use one of the following ...
IsVisible,
Exists,
TryGetClickablePoint,
State (e.g. OffScreen
The problem is that for this system, many controls return true for all of those even when the control cannot be seen! They also return a point with co-ordinates (-1, -1, -1, -1) whether the control is visible or not.
The only thing I have had any success with is using a try catch finally. I try to click on the control and if that fails, I go in to the catch block. That takes 60 seconds to time out though and I am getting intermittent issues with tests that run 9 times out of 10. Maybe the constant use of try catch is causing performance issues.
Is there an approach that actually works when all the standard approaches fail? I have noticed lots of other people asking these question are also testing WPF. Is there something WPF developers are doing to hide controls that makes CodedUI think they are still present and visible etc. Are they just behind something?
Many thanks in advance.
The solution was two-fold. Firstly I had to find the element and this was not working properly with my recorded steps. The element was buried too deeply in the system under test which is WPF (XAML). Secondly I had to prove I had found the element and for this I can't use TryGetClickablePoint, Exists, Top or Width. None of them seemed to work properly at all for my element. I had to use State.
public void Assert_MyElementShown()
{
#region Variable Declarations
WpfCustom uISurfaceCustom = this.UISysUnderTestClientShWindow.UIItemCustom1.UISurfaceCustom;
WpfCustom uIYAxisLabelsCustom = new WpfCustom();
#endregion
//Find the Element using it's Container and SearchProperties
uIYAxisLabelsCustom.Container = uISurfaceCustom;
uIYAxisLabelsCustom.SearchProperties[WpfControl.PropertyNames.ClassName] = "Uia.AxisLabelControl";
uIYAxisLabelsCustom.SearchProperties[WpfControl.PropertyNames.AutomationId] = "YAxisLabels";
//Use the State to find if it's on screen or not
var state = uIYAxisLabelsCustom.State;
if (state == Microsoft.VisualStudio.TestTools.UITest.Extension.ControlStates.Default)
{
//Element is visible, do stuff here!
}
else if (state == Microsoft.VisualStudio.TestTools.UITest.Extension.ControlStates.Offscreen)
{
//The control may exist, it may have location on screen and may even
//appear to be clickable according to coded ui framework but is is NOT
//shown on the screen.
}
}
You can try this approach for your application..if control properties are showing true for viable than we can go for height and width.Means if control is not visible in UI and but still all properties are showing true than check control height and width must be in -ve number.Than we can keep a assertion like
If control.height<0
Not visible in UI

Creating a GroupBox with _createChildControlImpl()

I tryed to create a group box with the _createChildControlImpl()-Methode but the layout looks like crap as you can see her http://tinyurl.com/odzgy3v
But when I implement it without _createChildControlImpl() it works fine: http://tinyurl.com/kwzvdm2
Could anybody please tell me what's the reason for this? Thanks in advance!
Have a look at your browser console - there is already a hint.
When you introduce child controls qooxdoo can't reuse the former default appearance of widgets because the appearance id changed (from "groupbox" to "widget/groupBox"). So you have to add your own appearance theme (which can simply forward by using an alias):
qx.Theme.define("test.myAwesomeTheme", {
extend : playground.theme.Appearance,
appearances :
{
"widget/groupBox" : "groupbox",
}
});
qx.theme.manager.Appearance.getInstance().setTheme(test.myAwesomeTheme);
I'm extending playground.theme.Appearance here which extends qx.theme.indigo.Appearance which again extends qx.theme.simple.Appearance. And their you have the groubox definition we are forwarding to.
Here is the complete playground sample.
You are supposed to implement _createChildControl, but not call it directly. Instead call getChildControl in your constructor and let it call _createChildControl, if needed, since it is also caching the result.
GroupBox seems to be a bad fit for what you want - it seems to assume identically sized and shaped elements inside its frame sub-widget, when filled from within the implementation of _createChildControl().
Use another Composite() inside the main container instead, add "Registration" as yet another child control of type label as the first child of the custom widget, and things will look much better (although not identical).
Quick and sloppy proof of concept: http://tinyurl.com/m7ykhta

UIPageViewController navigates to wrong page with Scroll transition style

My UIPageViewController was working fine in iOS 5. But when iOS 6 came along, I wanted to use the new scroll transition style (UIPageViewControllerTransitionStyleScroll) instead of the page curl style. This caused my UIPageViewController to break.
It works fine except right after I've called setViewControllers:direction:animated:completion:. After that, the next time the user scrolls manually by one page, we get the wrong page. What's wrong here?
My workaround of this bug was to create a block when finished that was setting the same viewcontroller but without animation
__weak YourSelfClass *blocksafeSelf = self;
[self.pageViewController setViewControllers:viewControllers direction:UIPageViewControllerNavigationDirectionForward animated:YES completion:^(BOOL finished){
if(finished)
{
dispatch_async(dispatch_get_main_queue(), ^{
[blocksafeSelf.pageViewController setViewControllers:viewControllers direction:UIPageViewControllerNavigationDirectionForward animated:NO completion:NULL];// bug fix for uipageview controller
});
}
}];
This is actually a bug in UIPageViewController. It occurs only with the scroll style (UIPageViewControllerTransitionStyleScroll) and only after calling setViewControllers:direction:animated:completion: with animated:YES. Thus there are two workarounds:
Don't use UIPageViewControllerTransitionStyleScroll.
Or, if you call setViewControllers:direction:animated:completion:, use only animated:NO.
To see the bug clearly, call setViewControllers:direction:animated:completion: and then, in the interface (as user), navigate left (back) to the preceding page manually. You will navigate back to the wrong page: not the preceding page at all, but the page you were on when setViewControllers:direction:animated:completion: was called.
The reason for the bug appears to be that, when using the scroll style, UIPageViewController does some sort of internal caching. Thus, after the call to setViewControllers:direction:animated:completion:, it fails to clear its internal cache. It thinks it knows what the preceding page is. Thus, when the user navigates leftward to the preceding page, UIPageViewController fails to call the dataSource method pageViewController:viewControllerBeforeViewController:, or calls it with the wrong current view controller.
I have posted a movie that clearly demonstrates how to see the bug:
http://www.apeth.com/PageViewControllerBug.mov
EDIT This bug will probably be fixed in iOS 8.
EDIT For another interesting workaround for this bug, see this answer: https://stackoverflow.com/a/21624169/341994
Here is a "rough" gist I put together. It contains a UIPageViewController alternative that suffers from Alzheimer (ie: it doesn't have the internal caching of the Apple implementation).
This class isn't complete but it works in my situation (namely: horizontal scroll).
As of iOS 12 the problem described in the original question seems to be almost fixed. I came to this question because I experienced it in my particular setup, in which it does still happen, hence the word "almost" here.
The setup I experienced this issue was:
1) the app was opened via a deep link
2) based on the link the app had to switch to a particular tab and open a given item there via push
3) described issue happened only when the target tab was not previously selected by user (so that UIPageViewController was supposed to animate to that tab) and only when setViewControllers:direction:animated:completion: had animated = true
4) after the push returning back to the view controller containing the UIPageViewController, the latter was found to be a big mess - it was presenting completely wrong view controllers, even though debugging showed everything was fine on the logic level
I supposed that the root of the problem was that I was pushing view controller very quick after setViewControllers:direction:animated:completion: called, so that the UIPageViewController had no chance to finish something (maybe animation, or caching, or something else).
Simply giving UIPageViewController some spare time by delaying my programmatic navigation in UI via
DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + 1) { ... }
fixed the issue for me. And it also made the programmatic opening of the linked item more user friendly visually.
Hope this helps someone in similar situation.
Because pageviewVC call multi childVC when swipe it. But we just need last page that visible.
In my case, I need to change index for segmented control when change pageView.
Hope this help someone :)
extension ViewController: UIPageViewControllerDelegate {
func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
guard let pageView = pageViewController.viewControllers?.first as? ChildViewController else { return }
segmentedControl.set(pageView.index)
}
}
This bug still exists in iOS9. I am using the same workaround that George Tsifrikas posted above, but a Swift version:
pageViewController.setViewControllers([page], direction: direction, animated: true) { done in
if done {
dispatch_async(dispatch_get_main_queue()) {
self.pageViewController.setViewControllers([page], direction: direction, animated: false, completion: {done in })
}
}
}
Another simple workaround in Swift: Just reset the UIPageViewController's datasource. This apparently clears its cache and works around the bug. Here's a method to go directly to a page without breaking subsequent swipes. In the following, m_pages is an array of your view controllers. I show how to find currPage (the index of the current page) below.
func goToPage(_ index: Int, animated: Bool)
{
if m_pages.count > 0 && index >= 0 && index < m_pages.count && index != currPage
{
var dir: UIPageViewController.NavigationDirection
if index < currPage
{
dir = UIPageViewController.NavigationDirection.reverse
}
else
{
dir = UIPageViewController.NavigationDirection.forward
}
m_pageViewController.setViewControllers([m_pages[index]], direction: dir, animated: animated, completion: nil)
delegate?.tabDisplayed(sender: self, index: index)
m_pageViewController.dataSource = self;
}
}
How to find the current page:
var currPage: Int
{
get
{
if let currController = m_pageViewController.viewControllers?[0]
{
return m_pages.index(of: currController as! AtomViewController) ?? 0
}
return 0
}
}
STATEMENT:
It seems that Apple has spotted that developers are using UIPageViewController in very different applications that go way beyond the
originally intended ones Apple based their design-choices on in the first place. Rather than using it in a gesture driven linear fashion
PVC is often used to programmatically jump to random
positions within a structured environment. So they have enhanced their implementation of UIPageViewController and the class is now calling both DataSource
callbacks
- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerBeforeViewController:(UIViewController *)viewController
- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController
after setting a new contentViewController on UIPageViewController with
[self.pageViewController setViewControllers:viewControllers direction:UIPageViewControllerNavigationDirectionForward animated:YES completion:nil];
even if an animated turn of pages rather suggests a linear progress in an e.g. page hierarchy like a book or PDF with consecutive pages. Although - I doubt that Apple from a HIG standpoint
is very fond of seeing PVC being used this way, but - it doesn't break backwards compatibility, it was an easy fix, so - they eventually did it. Actually it is just one more call of one of the two DataSource methods that is absolutely unnecessary in a linear environment where pages (ViewControllers) have already been cashed for later use.
However, even if this enhancement might come in very handy for certain use-cases the initial behavior of the class is NOT to be considered a bug. The fact that a lot of developers do - also in other
posts on SO that accuse UIPageViewController of misbehavior - rather emphasizes a widely spread misconception of its design, purpose and functionality.
Without trying to offend any of my fellow developers here in this great facility I nonetheless decided not to remove my initial 'disquisition' that clearly explains to the OP the mechanics of PVC and why his assumption is wrong that he has to deal with a bug here.
This might also be of use for any other fellow developer too who struggles with some intricacies in the implementation of UIPageViewController!
ORIGINAL ANSWER:
After having read all the answers over and over again - included the
accepted one - there is just one more thing left to say...
The design of UIPageViewController is absolutely FLAWLESS and all the
hacks you submit in order to circumvent an alleged bug is nothing but
remedies for your own faulty assumptions because you goofed it up in the
first place!!!
THERE IS NO BUG AT ALL! You are just fighting the framework. I'll explain why!
There is so much talk about page numbers and indices! These are concepts the
controller knows NOTHING about! The only thing it knows is - it is showing
some content (btw. provided by you as a dataViewController) and that it can
do something like a right/left animation in order to imitate a page turn.
CURL or SCROLL...!!!
In the pageViewController's world there only exists a current SPACE (let's call
it just this way to avoid confusion with pages and indices).
When you initially set a pageViewController it only minds about this very SPACE.
Only when you start panning its view it starts asking its DataSource what it
eventually should display in case a left/right flip should happen. When you start
panning to the left the PVC asks first for the BEFORE-SPACE and then for the
AFTER-SPACE, in case you start to the right it does it the other way round.
After the completed animation (a new SPACE is displayed by the PVC's view) the
PVC considers this SPACE as its new center of the universe and while it is at it, it
asks the DataSource about the one it still does not know anything about. In case of
a completed turn to the right it wants to know about the new AFTER space and in
case of a completed turn to the left it asks for a new BEFORE space.
The old BEFORE space (from before the animation) is in case of a completed turn to
the right completely obsolete and gets deallocated as soon as possible. The old center
is now the new BEFORE and the former AFTER is the new center. Everything just
shifted one step to the right.
So - no talk of 'which page' or 'whatever index' - just simply - is there a BEFORE or
an AFTER space. If you return NIL to one of the DataSource callbacks the PVC just
assumes it is at one extreme of your range of SPACES. If you return NIL to both
callbacks it assumes it is showing the one and only SPACE there is and will never
ever again call a DataSource callback anymore! The logic is up to you! You define
pages and indices in your code! Not the PVC!!!
For the user of the class there are two means of interacting with the PVC.
A pan-gesture that indicates whether a turn to the BEFORE/AFTER space is desired
A method - namely setViewControllers:direction:animated:completion:
This method does exactly the same than the pan gesture is doing. You are indicating the
direction (e.g. UIPageViewControllerNavigationDirectionBackward/Forward)
for the animation - if there is one intended - which in other words just means -> going to
BEFORE or AFTER...
Again - no mentioning of indices, page-numbers etc....!!!
It is just a programmatically way of achieving the same a gesture would!
And the PVC is doing right by showing the old content again when moving back
to the left after having moved to the right in the first place. Remember
- it is just showing content (that you provide) in a structured way - which is a 'single page turn' by design!!!
That is the concept of a page turn - or BOOK, if you like that term better!
Just because you goof it up by submitting PAGE 8 after PAGE 1 doesn't mean the PVC
cares at all about your twisted opinion of how a book should work. And the user of your
apps neither. Flipping to the right and back to the left should definitely result in reaching
the original page - IF done with an animation. And it is up to YOU to correct the goof by
finding a solution for the disaster. Don't blame it on the UIPageViewController. It is doing
its job perfectly!
Just ask yourself - would you do the same thing with a PAGE-CURL animation? NO ?
Well, neither should you with a SCROLL animation!!! An animated page turn is a page turn and only a page turn!
In either mode!
And if you decide to tear out PAGE 2 to PAGE 7 of your BOOK that's perfectly fine!
But just don't expect UIPageViewController to invent a non-existing PAGE 7 when turning back to the recent page unless YOU tell it that things have changed...
If you really want to achieve an uncoordinated jump to elsewhere, well - do it without an
animation! In most cases this will not be very elegant but - it's possible... -
And the PVC even plays nicely along! When jumping to a new SPACE without animation
it will ask you further down the road for both - the BEFORE and AFTER controller. So your application-logic can keep up with the PVC...
But with an animation you are always conveying - move to the previous/next space (BEFORE -
AFTER). So logically there is no need at all for the PVC to ask again about a space it already
knows about when animating page turns!!!
If you wanna see PAGE 7 when flipping back to the left after having animated from PAGE 1
to the right - well, I would say - that's definitely your very own problem!
And just in case you are looking for a better solution than the 'completion-block' hack from
the accepted answer (because with it you are doing work beforehand for something that might
possibly not even get used further down the road) use the gesture recognizer delegate:
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
Set your PVC's DataViewController here (without animation) if you really intend to go back
left to PAGE 7 and the DataSource will be asked for BEFORE and AFTER and you can submit
whatever page you like! With a flag or ivar that you should have stashed away when doing your uncontrolled
jump from PAGE 1 to 8 this should be no problem...
And when people keep on complaining about a bug in the PVC - doing 2 page turns when it is
supposed to do 1 turn only - point them to this article.
Same problem - triggering an un-animated setViewControllers: method within the transition gesture
will cause exactly the same havoc. You think you set the new center - the DataSource is asked
for the new BEFORE - AFTER dataController - you reset your index count... - Well, that seems OK...
But - after all that business the PVC ends its transition/animation and wants to know about the
next (still unknown to it) dataViewController (BEFORE or AFTER) and also triggers the DataSource. That's totally justified ! It needs to know where in its small BEFORE - CENTER - AFTER
world it is and be prepared for the next turn.
But your program-logic adds another index++ count to its logic and suddenly got 2 page turns !!!
And that is one off from where you think you are.
And YOU have to account for that! Not UIPageViewController !!!
That is exactly the point of the DataSourceProtocol only having two methods! It wants to be as generic as possible - leaving you the space and freedom to define your own logic and not being stuck with somebody else's special ideas and use-cases! The logic is completely up to you. And only because you find functions like
- (DataViewController *)viewControllerAtIndex:(NSUInteger)index storyboard:(UIStoryboard *)storyboard position:(GSPositionOfDataViewController)position;
- (NSUInteger)indexOfViewController:(DataViewController *)viewController;
in all the copy/pasted sample applications in the cloud doesn't necessarily mean that you have to eat that pre-cook food! Extend them any way you like! Just look above - in my signature you will find a 'position:' argument! I extended this to know later on if a completed page turn was a right or a left turn. Because the delegate unfortunately just tells you whether your turn completed or not! It doesn't tell you about the direction! But this sometimes matters for index-counting, depending on your application's need...
Go crazy - they are your's...
HAPPY CODING !!!

Win32 C API for redirecting minimize animation

I have seen RocketDock redirect the minimize animation in Vista so windows minimize to the dock, and am just curious how this was done. Is the actual minimize animation redirected to the dock, or is something like a hook to stop Windows from minimizing the window and RocketDock has a custom animation when the window is minimized?
I am working on an open source multi-monitor taskbar project called "OpenMMT." I've recently discovered (through many headaches) how to accomplish this.
The following explanation assumes that you know how to go about using RegisterShellHookWindow.
On the window procedure that will receive the shell hooks, look for HSHELL_GETMINRECT.
Now, from here on out is where I had problems. According to MSDN, the lparam member passed contains a pointer to a "SHELLHOOK" object. Which is true, however, I could not get it to work for the simple fact that the "rc" member of that structure, is a RECT that differs from the actual RECT structure in the Windows header files. The RECT in the header files uses LONG for its members, were as on here, we want SHORT.
Anyways, here's a snippet on how I accomplished this.
Structures to define:
typedef struct {
SHORT left;
SHORT top;
SHORT right;
SHORT bottom;
} REALRECT, *LPREALRECT;
typedef struct {
HWND hWnd;
REALRECT rc;
} DOCUMENT_ME_RIGHT_MICROSOFT, *LPDOCUMENT_ME_RIGHT_MICROSOFT;
Then on the Window Procedure:
case HSHELL_GETMINRECT:
{
LPDOCUMENT_ME_RIGHT_MICROSOFT lpShellHook = (LPDOCUMENT_ME_RIGHT_MICROSOFT)lParam;
// lpShellHook now contains all the info. If you want to change the location
// of the animation, simply change the lpShellHook->rc members to point
// to the right coordinates and then return TRUE;
return TRUE;
}
When minimizing programs from my application I encountered some instances where the animation would default back to the original one. I resolved this by minimizing them like so:
void MinimizeApp(HWND hWnd) {
SetForegroundWindow(hWnd);
ShowWindowAsync(hWnd, SW_MINIMIZE);
}
If you want more info regarding my project or you just want to peek at the source, feel free to do so at https://github.com/Fafson/OpenMMT
The ptMinPosition member of the WINDOWPLACEMENT structure specifies the coordinates of the window when it is minimized, so SetWindowPlacement function can be used to that effect. But some testing shows the window should not have a task bar button for that to work (i.e. no WS_EX_APPWINDOW).
I don't know how RocketDock works, but I guess this could be achieved by installing a global WH_CBT hook, and acting upon (setting the ex_style and then setting minimized coordinates) HCBT_MINMAX notification.
You can use the AnimateWindow API function, and pass it e.g. AW_HOR_POSITIVE | AW_VER_POSITIVE to get a diagonal animation.
I'd start with a global hook catching WM_SYSCOMMAND/SC_MINIMIZE, and use AnimateWindow to target the top right corner.
If this doesn't provide the desired effect, the next step would be to use WM_PRINT/WM_PRINTCLIENT to get a copy of the window into a bitmap (I believe this is what AnimateWindow does internally), then hiding the window and doing my own animation.

Microsoft Surface: "Read" the tag value of an IdentityTag

is it possible to read the value of an IdentityTag if you place it on the TagVisualizer, without having initalized it before?
I would like to use the tags for registering a new object on the Surface but having all the "free" IdentityTags in a Collection for initalizing them all... There must be a better way to do in I think.
But the TagVisualizer doesn't seem to do anything when you put a tag on it that it doesn't know.
If I understand correctly, you'll need to start by setting up your TagVisualizer with a TagVisualizationDefinition with a Matches method that always returns true.

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