I have a ListView and am using the SelectedItem to call a command and show a modal view.
However, I have an issue where the user can tap multiple times on the listview row and multiple modal views are shown before the view has loaded. Granted this only happens on slower devices.
This is is caused because the command doesn't have any call back.
I wouldn't normally paste code here, but in this case I thought it was more descriptive to provide a screen shot.
I've looked into the AsyncCommands but these seem to be used more to handle errors.
I'm currently thinking about a subscribe approach which is triggered when the modal is exited, however I think there must be another way I haven't thought of.
Can you try using a Boolean as IsSelected & make IsSelected true when user clicks an item from list & change your condition in setter as below. When your operations are done reset the flag.
This was, there wont not be any duplication of modals. This is what I understood from your question, if there's something else, please let me know.
if( _locationAssetSelected || !IsSelected )
{
IsSelected = true;
_locationAssetSelected = value;
..... //your code
_locationAssetSelected = null;
IsSelected = false;
}
You could move the logic to the command to make sure it doesn't execute multiple times. This is a snippet on the sample/template Forms app which uses this method as a command. Lock seems unnecessary.
async void OnItemSelected(Item item)
{
//lock (selectLock)
//{
if (item == null || selectionOn)
return;
selectionOn = true;
//}
System.Diagnostics.Debug.WriteLine($"{item.Text} selected");
// This will push the ItemDetailPage onto the navigation stack
await Shell.Current.GoToAsync($"{nameof(ItemDetailPage)}?{nameof(ItemDetailViewModel.ItemId)}={item.Id}");
selectionOn = false;
}
Related
I load a Canvas prefab at runtime when an event occurs. The canvas simply has a Panel inside it, which in turn has 2 buttons. I'm trying to add OnClick events to both these buttons in the script, but it only works for the first button somehow!
I have the following two lines of code one after the other:
GameObject.Find("RestartButton").GetComponent<Button>().onClick.AddListener(() => RestartClicked());
GameObject.Find("ViewButton").GetComponent<Button>().onClick.AddListener(() => ViewClicked());
The callback only works for the RestartButton, and not for the ViewButton.
It may well be a very small thing, but I searched Google and Bing extensively and remain clueless, so any help would be appreciated.
Thanks!
Edit:
The script instantiates the prefab and tries to reference the two buttons in the prefab through GameObject.Find(), given that once Instantiate is called the Canvas should be active in the heirarchy.
I also opened up the part of the code that attaches buttons to the listener for debugging. I dont think it attaches the listener at all.
void Start () {
SetupScene();
var prefab = Resources.Load("RestartOrViewPrefab");
if (prefab == null)
{
Debug.LogAssertion("Prefab missing!");
return;
}
restartCanvas = (GameObject)Instantiate(prefab);
Button btn = GameObject.Find("ViewButton").GetComponent<Button>();
btn.onClick.RemoveAllListeners();
btn.onClick.AddListener(() => ViewToggle());
Button btn2 = GameObject.Find("RestartButton").GetComponent<Button>();
btn2.onClick.AddListener(() => RestartClicked());
}
private void RestartClicked()
{
Debug.Log("RESTARTING");
SetupScene();
}
private void ViewToggle()
{
Debug.Log("TOGGLE");
if (freshStart)
{
//Something here
freshStart = false;
}
else
{
//Something else here
freshStart = true;
}
}
So I took two days to solve my problem. Apparently, doing a GameObject.Find() for a GameObject within a prefab that you just instantiated doesn't work. We always need to use the GameObject that the Instantiate() method returns to find any component within the prefab.
The code I used to make my scene work may not be the best solution if your prefab is very big/complex (say you have 15 buttons and need to do something with one), but it sure does work. :)
I replaced the following lines of code:
Button btn = GameObject.Find("ViewButton").GetComponent<Button>();
btn.onClick.RemoveAllListeners();
btn.onClick.AddListener(() => ViewToggle());
Button btn2 = GameObject.Find("RestartButton").GetComponent<Button>();
btn2.onClick.AddListener(() => RestartClicked());
With the following lines of code:
Button[] buttons = restartCanvas.GetComponentsInChildren<Button>();
foreach(Button but in buttons)
{
if(but.gameObject.name == "RestartButton")
but.onClick.AddListener(() => RestartClicked());
else if(but.gameObject.name == "ViewButton")
but.onClick.AddListener(() => ViewToggle());
}
So I just reused the restartCanvas that I got a reference to.
restartCanvas = (GameObject)Instantiate(prefab);
Hope this helps someone. :)
I answered this on another post, but I'll answer it here for people that still need this info.
The GameObject your instantiated button is a child of must have a CanvasRenderer component on it.
I'm not sure why this works, but it does.
Once the parent of the button GameObject has the CanvasRenderer on it, you can call myButton.onClick.AddListener(() => MyMethod(MyArgs)); as you normally would.
Ok make sure you are not getting any null reference error, and check tht spelling of you buttons , output some debug logs in your second function to see if its even reaching there
I am looking to make the enter key behave exactly like the tab key on a form.
I am stuck on the fireEvent section.
var inputs = $$('input, textarea');
$each(inputs,function(el,i) {
el.addEvent('keypress',function(e) {
if(e.key == 'enter') {
e.stop();
el.fireEvent('keypress','tab');
}
});
});
How do I fire a keypress event with a specified key? Any help would be greatly appreciated.
this will work but it relies on dom order and not tabindex
var inputs = $$('input,textarea');
inputs.each(function(el,i){
el.addEvent('keypress',function(e) {
if(e.key == 'enter'){
e.stop();
var next = inputs[i+1];
if (next){
next.focus();
}
else {
// inputs[0].focus(); or form.submit() etc.
}
}
});
});
additionally, textarea enter capture? why, it's multiline... anyway, to do it at keyboard level, look at Syn. https://github.com/bitovi/syn
the above will fail with hidden elements (you can filter) and disabled elements etc. you get the idea, though - focus(). not sure what it will do on input[type=radio|checkbox|range] etc.
p.s. your code won't work because .fireEvent() will only call the bound event handler, not actually create the event for you.
Take a look at the class keyboard (MooTools More).
It can fire individual events for keys and provides methodology to disable and enable the listeners assigned to a Keyboard instance.
The manual has some examples how to work with this class, here's just a simple example how I implemented it in a similar situation:
var myKeyEv1 = new Keyboard({
defaultEventType: 'keydown'
});
myKeyEv1.addEvents({
'shift+h': myApp.help() // <- calls a function opening a help screen
});
Regarding the enter key in your example, you have to return false somewhere to prevent the enter-event from firing. Check out this SO post for more details.
I'm trying to develop a ff addon that allows a user to right-click on a form element and perform a task associated with it.
Unfortunately somebody decided that the context menu shouldn't appear for form inputs in ff and despite long discussions https://bugzilla.mozilla.org/show_bug.cgi?id=433168, they still don't appear for checkboxes, radios or selects.
I did find this: https://developer.mozilla.org/en-US/docs/Offering_a_context_menu_for_form_controls but I cannot think how to translate the code to work with the new add-on SDK.
I tried dumping the javascript shown into a content script and also via the observer-service but to no avail.
I also cannot find the source for the recommended extension https://addons.mozilla.org/en-US/firefox/addon/form-control-context-menu/ which considering it was 'created specifically to demonstrate how to do this' is pretty frustrating.
This seems like very basic addon functionality, any help or links to easier documentation would be greatly appreciated.
** UPDATE **
I have added the following code in a file, required from main, that seems to do the trick.
var {WindowTracker} = require("window-utils");
var tracker = WindowTracker({
onTrack: function(window){
if (window.location.href == "chrome://browser/content/browser.xul") {
// This is a browser window, replace
// window.nsContextMenu.prototype.setTarget function
window.setTargetOriginal = window.nsContextMenu.prototype.setTarget;
window.nsContextMenu.prototype.setTarget = function(aNode, aRangeParent, aRangeOffset) {
window.setTargetOriginal.apply(this, arguments);
this.shouldDisplay = true;
};
};
}
, onUntrack: function(window) {
if (window.location.href == "chrome://browser/content/browser.xul") {
// In case we were called because the extension is uninstalled - restore
// original window.nsContextMenu.prototype.setTarget function
window.nsContextMenu.prototype.setTarget = window.setTargetOriginal;
};
}
});
Unfortunately this still does not bring up a context menu for disabled inputs, but this is not a show-stopper for me.
Many Thanks
The important piece of code in this extension can be seen here. It is very simple - it replaces nsContextMenu.prototype.setTarget function in each browser window and makes sure that it sets shouldDisplay flag for form controls.
The only problem translating this to Add-on SDK is that the high-level modules don't give you direct access to browser windows. You have to use the deprecated window-utils module. Something like this should work:
var {WindowTracker} = require("sdk/deprecated/window-utils");
var tracker = WindowTracker({
onTrack: function(window)
{
if (window.location.href == "chrome://browser/content/browser.xul")
{
// This is a browser window, replace
// window.nsContextMenu.prototype.setTarget function
}
},
onUntrack: function(window)
{
if (window.location.href == "chrome://browser/content/browser.xul")
{
// In case we were called because the extension is uninstalled - restore
// original window.nsContextMenu.prototype.setTarget function
}
}
});
Note that WindowTracker is supposed to be replaced in some future SDK version. Also, for reference: nsContextMenu implementation
is there anyway to programmatically dismiss the drop-down list of an autocompletebox? my use case is as follows.
MainPage.xaml passes a value to SearchPage.xaml (i.e. /SearchPage.xaml?query=someText).
in SearchPage.xaml.cs, i set,
autoCompleteBox.Text = NavigationContext.QueryString["query"].
at this point, the drop-down list of suggested matches shows up. i don't want this behavior when the page is just navigated to.
i also tried the following to dismiss the drop-down list but it didn't help.
autoCompleteBox.Text = NavigationContext.QueryString["query"];
autoCompleteBox.IsDropDownOpen = false;
the drop-down list seems to go away from the AutoCompleteBox when it loses focuses, but i don't see a property/field to set to make it lose focus.
any help is appreciated.
well, i tinkered a bit and came up with a kludge. in the constructor of SearchPage.xaml.cs i have the following code.
autoCompleteBox.TextFilter += DummyFilter;
autoCompleteBox.GotFocus += (s,args) => {
if(!isAutoCompleteBoxInit) {
autoCompleteBox.TextFilter -= DummyFilter;
autoCompleteBox.TextFilter += RealFilter;
}
}
DummyFilter looks like the following.
bool DummyFilter(string search, string value) { return false; }
RealFilter looks like the following.
bool RealFilter(string search, string value) {
if(null != value) return value.ToLower().StartsWith(search.ToLower());
}
in my OnNavigatedTo method, is where i set, autoCompleteBox.Text = NavigationContext.QueryString["query"]. so when i do this now, the DummyFilter will always return false, so the drop-down list goes away. when the user focuses in on the AutoCompleteBox, i check if the correct Filter was already attached to the TextFilter property, if not, then i do a switch.
hope this helps some of you.
Is there any other focusable control on the page? Just set the focus somewhere else, and your problem should be solved.
When you have changed the text of the AutoCompleteBox the dropdown will open. Only when the user has changed the text and there is a match then the dropdown will close.
Just change userInitiated to true and when there is a match the dropdown will close.
private void UpdateTextCompletion(bool userInitiated)
{
userInitiated = true; ...
I have some validation code which should display the max / min of a control when a bad value is entered.
In my constructor I do this:
m_wndToolTip = gcnew ToolTip(this->components);
m_wndToolTip->AutoPopDelay = 5000;
m_wndToolTip->InitialDelay = 10;
m_wndToolTip->ReshowDelay = 250;
m_wndToolTip->ShowAlways = true;// Force the ToolTip text to be displayed whether or not the form is active.
This is my validation reflection code:
void MyGUI::IndicateValidationResult(Windows::Forms::Control^ control, bool isValid, String^ invalidReason)
{
// If the validation failed, make the background red. If not, turn it white.
if( isValid )
{
control->BackColor = Drawing::Color::White;
m_wndToolTip->Hide(control);
}
else
{
control->BackColor = Drawing::Color::LightCoral;
m_wndToolTip->Show(invalidReason, control);
}
}
...which is called from varous ValueChanged methods in my text boxes. I've tried using show and also a combination of SetToolTip and active = true and nothing seems to work.
I've seen another question asking about tooltips and have tried setting a nearby label in the call to show but that doesn't fix it either. The tooltip is a member variable in my System::Windows::Forms::Form derived form to stop it going out of scope.
Am I missing something obvious?
Your code worked fine when I tried it, there's no obvious mistake that I can see. I called it like this, using a Validating event of a text box:
bool ok;
System::Void textBox1_Validating(System::Object^ sender, System::ComponentModel::CancelEventArgs^ e) {
e->Cancel = !ok;
IndicateValidationResult(textBox1, ok, "invalid");
ok = !ok;
}
Beware that ToolTip can be cranky. The native Windows component has a "feature" that prevents a tooltip from showing again when it timed out before. The ErrorProvider component is a better mouse trap to get this done.