Some questions to the Force Touch Menu:
Now when I perform a Force Touch and press one of my menu Items, the whole InterfaceController, where my Menu is implemented is loading new.
Is this avoidable?
I've implemented a menu with 4 menuItems for my InterfaceController.
With one of this menuItems, I want to enable/disable the haptic Feedback of my Buttons.
My button methods are like this:
- (IBAction) but1Pressed {
[[WKInterfaceDevice currentDevice] playHaptic:WKHapticType.Click];
// Do something
}
How can I disable the TapticEngine, if the user disables it ind the ForceTouchMenu?
No, as by today that's not possible.
If I understand you properly, you need a BOOL which defines whether the app should perform haptic feedback when a button in your interface controller is being pressed.
To realise that, implement the following:
BOOL shouldGiveTapticFeedback = YES
Then you need a method to change this BOOL when the corresponding menu item is being pressed:
- (IBAction) tapticFeedbackChangeButtonPressed {
//change BOOL value
shouldGiveTapticFeedback = !shouldGiveTapticFeedback
}
Finally, you need to check whether the taptic feedback should be played, when a button in your interface controller is being pressed:
- (IBAction) interfaceButtonPressed {
if(shouldGiveTapticFeedback) {
//play sound
[[WKInterfaceDevice currentDevice] playHaptic:WKHapticType.Click];
}
}
No, that's not possible either.
Related
I am building a Xamarin Forms mobile app that runs in Android on a Zebra scanner. I flip 2 different StackLayouts to IsVisble true/false to display different stuff in the UI. (StackLayout1 and StackLayout2)
The customer wants the user to be able to use the app entirely from the hardware keyboard on the scanner. So I have used the device Settings so that it never displays the virtual keyboard (I don’t think that matters for the issue I am having.)
I am overriding DispatchKeyEvent in a PageRenderer in the Android project and everything is working great … except.
The problem case:
StackLayout1 is displayed
the user taps an Entry control, putting the focus there
the user taps a button in the UI
the app displays StackLayout2
at this point the DispatchKeyEvent never fires no matter what key I press on the device keyboard
If an Entry box does NOT get the focus (step #2 above) the DispatchKeyEvent always fires in StackLayout2 and the StackLayouts display as expected.
If I programatically put the focus in an Entry box in StackLayout2 at step #3 above the DispatchKeyEvent fires fine.
That is not an OK solution. I have tried to progamatically put the focus on StackLayout2, and that code seems to do what is expected but DispatchKeyEvent does not fire.
Maybe I need to do something in the Android-project PageRenderer so that it is aware of StackLayout2 when it is made IsVisible = true.
Update 2: I found that I did NOT need custom StackLayouts. The solution which I posted below does not include any of this stuff I am describing in Update 1 (sorry, if that's confusing).
Update 1:
I added a ViewRenderer for both StackLayouts, and the code is hitting the OnElementChanged event when StackLayout2's IsVisible property flips to true, just great. Although the problem case is the same: DispatchKeyEvent does not fire once StackLayout2 is displayed, if an EntryBox had the focus in StackLayout1
Here is the OnElementChanged part of the new StackLayout ViewRenders
async void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
{
switch (e.PropertyName)
{
case "IsVisible":
if (Element.IsVisible)
{
if (sender is StackLayout)
{
this.FocusableViewAvailable(this); // if I comment these 2 lines out I get the same bad result
this.Focusable = true; // if I comment these 2 lines out I get the same bad result
this.FocusableInTouchMode = true;
var dd = this.RequestFocus(); // this is always false
var ee = this.IsFocused; // this is always false
}
}
break;
}
}
Also, as I am pointing out in the comments ^ there, IsFocused is always false.
Ideas?
My hunch, "Maybe I need to do something in the Android project PageRenderer" was correct. In the DispatchKeyEvent I had to make the MainPage have the focus when the keypress was handled.
Here is what the DispatchKeyEvent looks like now (notice the comments):
public override bool DispatchKeyEvent(KeyEvent ke)
{
// MainPage.ReceiveKeyPress(e); is the method that this method returns to
bool KeyPressWasHandled = false;
KeyPressWasHandled = (Element as MainPage).ReceiveKeyPress(ke);
if (KeyPressWasHandled)
{
// this next block seems to be needed so that this class
// continues to receive the keypress event after an Entry box has had the focus
this.Focusable = true;
this.FocusableInTouchMode = true;
this.RequestFocus();
return true; // returning true tells the parent class that the keypress has been handled
} else
{
try
{
return base.DispatchKeyEvent(ke);
}
Now the "problem case" in my initial post is no longer a problem.
NOTE: I found that I did NOT need the custom ViewRenderers that I had made for the StackLayouts.
I am creating an application that should work on desktop and some mobile platforms.
The following example creates and connects my portrait/landscape buttons, in a group, to a slot, on the release signal.
m_landscapeRadio = new QRadioButton(QObject::tr("Landscape "));
m_portraitRadio = new QRadioButton(QObject::tr("Portrait "));
m_orientationGroup.addButton(m_landscapeRadio, 0);
m_orientationGroup.addButton(m_portraitRadio, 1);
m_orientationGroup.setExclusive(true);
m_landscapeRadio->setChecked(true);
connect(&m_orientationGroup, SIGNAL(buttonReleased(int)), this, SLOT(orientationSlot(int)));
But I found a weird situation:
Assume landscape button is checked. If I press and drag away from the portrait radio button, the slot action is performed (for the portrait option) but the portrait button is not checked.
I would like the action not to be performed.
For now...
In the orientationSlot I test the argument and set the checked value myself... Though I really expected the buttons to know to do that themselves.
But I think it is more expected by users that, if the press a button and change their mind, to be able to drag away from the button and not have the action be performed.
I can handle verifying if the check really happened in the action slot, and either check or discard the action depending on how I will think the user experience is better...
If I want the buttons to be checked and to perform the action as well:
void MyWidget::orientationSlot(int checked)
{
if(checked) m_portraitRadio->setChecked(true);
else m_landscapeRadio->setChecked(true);
.... actual actions
}
If I want the action not to be performed when the user drags away from the button (my preferred option):
void MyWidget::orientationSlot(int checked)
{
if(m_orientationGroup.checkedId() != checked) return;
.... actual actions
}
I use QRadioButton and handle mouse button being released event for reacting
on radio button being switched. It causes problems altogether with dragging event. I would like to either get the button
to be checked, or the action not to be performed.
http://doc.qt.io/qt-5/qradiobutton.html
Whenever a button is switched on or off, it emits the toggled()
signal. Connect to this signal if you want to trigger an action each
time the button changes state. Use isChecked() to see if a particular
button is selected.
Either you connect the radio button to the handler explicitly or the whole group: http://doc.qt.io/qt-5/qbuttongroup.html#buttonToggled
void QButtonGroup::buttonToggled(QAbstractButton *button, bool
checked)
This signal is emitted when the given button is toggled. checked is
true if the button is checked, or false if the button is unchecked.
Note: Signal buttonToggled is overloaded in this class. To connect to
this one using the function pointer syntax, you must specify the
signal type in a static cast, as shown in this example:
connect(buttonGroup, static_cast<void(QButtonGroup::*)
(QAbstractButton *, bool)>(&QButtonGroup::buttonToggled),
[=](QAbstractButton *button, bool checked) {
if (button == m_portraitRadio) {
// Portrait (un)checked
if (checked)
{
// checked!
}
}
/* ... */ });
How do I pop up an UIAlertView when the back button of a UINavigationBar (controlled by a UINavigationController) was tapped? Under certain conditions, I want to ask the user an "Are you sure?" type of question so he could either abort the action and stay on the current view or pop the navigation stack and go to the parent view.
The most appealing approach I found was to override ShouldPopItem() on UINavigationBar's Delegate.
Now, there is a quite similar question here: iphone navigationController : wait for uialertview response before to quit the current view
There are also a few other questions of similar nature, for example here:
Checking if a UIViewController is about to get Popped from a navigation stack?
and How to tell when back button is pressed in a UINavigationControllerStack
All of these state "subclass UINavigationController" as possible answers.
Then there is this one that reads like subclassing UINavigationController is generally not a good idea:
Monotouch: UINavigationController, override initWithRootViewController
The apple docs also say that UINavigationController is not intended to be subclassed.
A few others state that overriding ShouldPopItem() is not even possible when using a UINavigationController as that does not allow to assign a custom/subclassed UINavigationBarDelegate to the UINavigationBar.
None of my attempts of subclassing worked, my custom Delegate was not accepted.
I also read somewhere that it might be possible to implement ShouldPopItem() within my custom UINavigationController since it assigns itself as Delegate of its UINavigationBar.
Not much of a surprise, this didn't work. How would a subclass of UINavigationController know of the Methods belonging to UINavigationBarDelegate. It was rejected: "no suitable method found to override". Removing the "override" keyword compiled, but the method is ignored completely (as expected). I think, with Obj-C one could implement several Protocols (similar to Interfaces in C# AFAIK) to achieve that. Unfortunately, UINavigationBarDelegate is not an Interface but a Class in MonoTouch, so that seems impossible.
I'm pretty much lost here. How to override ShouldPopItem() on UINavigationBar's Delegate when it is controlled by a UINavigationController? Or is there any other way to pop up an UIAlertView and wait for it's result before possibly popping the navigation stack?
This post is a bit old, but in case you're still interested in a solution (still involves subclassing though):
This implements a "Are you sure you want to Quit?" alert when the back button is pressed, modified from the code here: http://www.hanspinckaers.com/custom-action-on-back-button-uinavigationcontroller/
Turns out if you implement the UINavigationBarDelegate in the CustomNavigationController, you can make use of the shouldPopItem method:
CustomNavigationController.h :
#import <Foundation/Foundation.h>
#interface CustomNavigationController : UINavigationController <UIAlertViewDelegate, UINavigationBarDelegate> {
BOOL alertViewClicked;
BOOL regularPop;
}
#end
CustomNavigationController.m :
#import "CustomNavigationController.h"
#import "SettingsTableController.h"
#implementation CustomNavigationController
- (BOOL)navigationBar:(UINavigationBar *)navigationBar shouldPopItem:(UINavigationItem *)item {
if (regularPop) {
regularPop = FALSE;
return YES;
}
if (alertViewClicked) {
alertViewClicked = FALSE;
return YES;
}
if ([self.topViewController isMemberOfClass:[SettingsTableViewController class]]) {
UIAlertView * exitAlert = [[[UIAlertView alloc] initWithTitle:#"Are you sure you want to quit?" message:nil delegate:self cancelButtonTitle:#"Cancel" otherButtonTitles:#"Yes", nil] autorelease];
[exitAlert show];
return NO;
}
else {
regularPop = TRUE;
[self popViewControllerAnimated:YES];
return NO;
}
}
-(void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {
if (buttonIndex == 0) {
//Cancel button
}
else if (buttonIndex == 1) {
//Yes button
alertViewClicked = TRUE;
[self popViewControllerAnimated:YES];
}
}
#end
The weird logic with the "regularPop" bool is because for some reason just returning "YES" on shouldPopItem only pops the navbar, not the view associated with the navBar - for that to happen you have to directly call popViewControllerAnimated (which then calls shouldPopItem as part of its logic.)
For reference, the route I took after giving up on ShouldPopItem() is to replace the back button with a UIBarButtonItem that has a custom UIButton assigned as it's CustomView. The UIButton is crafted to look like the original back button using two images for the normal and the pressed state. Finally, hiding the original back button is required.
Way too much code for what it's supposed to do. So yeah, thanks Apple.
BTW: Another possibility is creating a UIButton with the secret UIButtonType 101 (which is actually the back button) but I avoided this as it may break at any later iOS version.
Override only UINavigationBarDelegate methods in a UINavigationController subclass and it should simply work. Be cautious that the protocol methods are also called when you push or pop a view controller from inside your code and not only when the back button is pressed. This is because them are push/pop notifications not button pressed actions.
Xamarin does provide the IUINavigationBarDelegate interface to allow you to implement the UINavigationBarDelegate as part of your custom UINavigationController class.
The interface however does not require that the ShouldPopItem method be implemented. All the interface does is add the appropriate Protocol attribute to the class so it can be used as a UINavigationBarDelegate.
So in addition you need to add the ShouldPopItem declaration to the class as follows:
[Export ("navigationBar:shouldPopItem:")]
public bool ShouldPopItem (UINavigationBar navigationBar, UINavigationItem item)
{
}
I've merged this solution with a native Obj-C solution. This is the way I'm currently handling the cancellation of the BACK button in iOS
It seems that it is possible to handle the shouldPopItem method of the NavigationBar in this way:
Subclass a UINavigationController
Mark your custom UINavigationController with the IUINavigationBarDelegate
Add this method with the Export attribute
[Export ("navigationBar:shouldPopItem:")]
public bool ShouldPopItem (UINavigationBar navigationBar, UINavigationItem item)
{
}
Now you can handle popping in the ShoulPopItem method. An example to this is to create an interface like this
public interface INavigationBackButton
{
// This method should return TRUE to cancel the "back operation" or "FALSE" to allow normal back
bool BackButtonPressed();
}
Then mark your UIViewController which needs to handle the back button with this interface. Implement something like this
public bool BackButtonPressed()
{
bool needToCancel = // Put your logic here. Remember to return true to CANCEL the back operation (like in Android)
return needToCancel;
}
Then in your ShouldPopItem Implementation have something like this
tanks to: https://github.com/onegray/UIViewController-BackButtonHandler/blob/master/UIViewController%2BBackButtonHandler.m
[Export("navigationBar:shouldPopItem:")]
public bool ShouldPopItem(UINavigationBar navigationBar, UINavigationItem item)
{
if (this.ViewControllers.Length < this.NavigationBar.Items.Length)
return true;
bool shouldPop = true;
UIViewController controller = this.TopViewController;
if (controller is INavigationBackButton)
shouldPop = !((INavigationBackButton)controller).BackButtonPressed();
if (shouldPop)
{
//MonoTouch.CoreFoundation.DispatchQueue.DispatchAsync
CoreFoundation.DispatchQueue.MainQueue.DispatchAsync(
() =>
{
PopViewController(true);
});
}
else
{
// Workaround for iOS7.1. Thanks to #boliva - http://stackoverflow.com/posts/comments/34452906
foreach (UIView subview in this.NavigationBar.Subviews)
{
if(subview.Alpha < 1f)
UIView.Animate(.25f, () => subview.Alpha = 1);
}
}
return false;
}
In Qt, either implementing keyPressEvent or creating a QAction and assigning it a key combination allow me to act based on the keyboard.
Which of these methods is generally preferred?
You should use QAction whenever the same event that is triggered by the key sequence you want may be triggered through other ways like from a menu, toolbar or other buttons. This way you can use the same action on several widgets that should do the same trick.
Excerpt from QAction doc:
The QAction class provides an abstract
user interface action that can be
inserted into widgets.
In applications many common commands
can be invoked via menus, toolbar buttons, and
keyboard shortcuts. Since the user
expects each command to be performed
in the same way, regardless of the
user interface used, it is useful to
represent each command as an action.
I'd prefer to overwrite the keyPressEvent. I don't like the idea of a QAction "lying around somewhere". Just overwrite the keyPressedEvent. I usually do it with a switch-case in which I check the pressed key. Just don't forget to call the keyPressEvent of the base class if you don't want to disable the standard behaviour of a key. Additionally you can check if a "modifier" is pressed while a keyPressEvent occurs. (e.g. Shift or Ctrl). IMHO for general purposes overwriting the keyPressEvent is better than creating invisible, secret actions, unless you want your application to contain all those actions visible for the user.
void my_widget::keyPressEvent( QKeyEvent* p_event )
{
bool ctrl_pressed = false;
if( p_event->modifiers() == Qt::ControlModifier )
{
ctrl_pressed = true;
}
switch( p_event->key() )
{
case Qt::Key_F:
focus_view();
break;
case Qt::Key_I:
if( ctrl_pressed )
{
toggle_interface();
}
else
{
QWidget::keyPressEvent( p_event );
}
break;
case Qt::Key_Return: // return key
case Qt::Key_Enter: // numpad enter key
update_something();
break;
default:
QSpinBox::keyPressEvent( p_event );
}
}
Would depend on what you need it for.
Is it for a menu like action that may be triggered by a menu, button, toolbar too, then go for the QAction. Especially if this action should work all over your program, not only in a single widget.
Is it more like a local activity in a single widget (say for example controlling movement in a game), I would use the keypress event.
I need to disable delete button GLOBALLY based on some condition?
The following solutions will not work for me:
http://csharpbits.notaclue.net/2009/07/securing-dynamic-data-preview-4-refresh.html
http://csharpbits.notaclue.net/2008/05/dynamicdata-miscellaneous-bits-part-6.html
Again, I do not want to go into every list and detail page and disable it there.
Why not just extend/inherit from button. You could make your own button that "knows" how to check if it should be hidden:
public class MyButton : Button
{
public void HiddenCheck()
{
bool visible = true;
//Check to see if the button should be hidden
this.Visible = visible;
}
}
Then, just use this button instead of the "System.Web.UI.WebControls.Button" button wherever you need the delete button functionality.
-Make that "Enabled." I read the post again, and I guess you aren't trying to "hide" the button, but disable it. The idea is the same though.