The basic structure of views
AppView > PageView > XView, YView, ZView.
Where ">" is a "has a" association. How can one easily broadcast event from ZView to its other siblings XView and YView
Thanks
Related
I have a CustomScrollView with several children. One children should always be displayed but the other ones should be displayed depending on a condition:
CustomScrollView(
controller: articleState.scrollController,
slivers: [
ArticleDetailPageHeader(widget.articleShort), // <- should always be displayed
...condition
? _buildShimmerWidgets() // returns List<Widget>
: _buildArticleWidgets(context, articleState), // ยดยด
],
)
This is working. But I would like to use a AnimatedSwitcher so the UI looks a bit smoother.
I look into AnimatedSwitcher and it takes a child of the type Widget. Now that is the Problem! I have a List<Widget. Is there any workaround for this?
I hope my problem is clear, let me know if you need any more info!
Try to use a Column as the child for the AnimatedSwitcher and then pass the List<Widget> as children for the Column.
I am trying to create a List which behaves like, for example, the Finder Menu on my Mac. In other words if I click on a List Item, keep my mouse down and move up and down the List I want the Selected Item to change.
In my Flex application if I click on my List and then, with the mouse still down, move up and down the List the Selected Item remains the same.
Any advice would be gratefully received.
Thanks
In StackOverflow tradition I am posting a solution to my own problem after working at it more:
I had an ItemRenderer on my List. In the ItemRenderer I declared a variable to hold a reference to the owning List.
private var _parentList:List;
In the 'set data' function I set this variable to the owner List.
override public function set data(value:Object):void {
super.data = value;
// Check to see if the data property is null.
if (value == null)
return;
// If the data property is not null.
// Get a reference to the parent list.
_parentList = this.owner as List;
...
I then added an EventListener to listen for MouseDown events.
// Attach an eventListener to the ItemRenderer.
this.addEventListener(MouseEvent.MOUSE_OVER, onMouseOver);
...
My onMouseOver handler looks like this.
private function onMouseOver(event:MouseEvent):void {
//trace(data.LocationName);
if (event.buttonDown == true) {
_parentList.selectedIndex = itemIndex;
}
}
So with this in place I can mouse-down on my List and keeping the mouse button depressed move up and down the List with the List Item beneath the cursor always being selected. The final piece to this is to ensure that the List responds to the selectedIndex being set by the ItemRenderer. When the user changes the selectedIndex property by interacting with the control, the control dispatches the change and changing events. When you change the value of the selectedIndex property programmatically, it dispatches the valueCommit event. To ensure I responded to my programmatic changing of the selected list item I added a handler to the valueCommit event.
<s:List
id="locationsList"
dataProvider="{presenter.locations}"
itemRenderer="itemrenderers.locationListItemRenderer"
useVirtualLayout="false"
width="1869.698" height="1869.698"
y="65.151" x="65.151"
borderVisible="true"
borderColor="{presenter.backgroundColour}"
contentBackgroundAlpha="0"
contentBackgroundColor="0xff336c"
labelField="label"
change="presenter.onLocationListChange(event)"
valueCommit="presenter.onLocationListValueCommit(event)">
<s:layout>
<s:BasicLayout />
</s:layout>
</s:List>
So far it seems to work fine. Hope it helps.
In sitecore, let's say I have an Item parentItem under it I want to create an item childItem which is based on Template templateItem, only when the childItem does not exist.
So the following code should only execute if the item not exist as child already.
parentItem.Add("Child Item", templateItem);
What do you mean saying item exists? Item with the same name? In Sitecore it is possible to have multiple items with the same item name. Those items in fact are not the same and have different IDs.
So in order to avoid creating another child item of the same template with the same name under the same parent, you need to upgrade your construction to the following:
string itemName = "Child item";
if(!dataItem.Children.Any(i=>i.Name == itemName && i.TemplateID == templateItem.ID))
{
dataItem.Add(itemName, templateItem);
}
Of course, it is not a good idea to have that clause from above everywhere, so you might want to automate that on every item creation. In order to do that, create your custom item:creating event handler with your custom one, like that:
<event name="item:creating">
<handler type="Your.Type, Your.Assembly.Name" method="OnItemCreating" />
And within OnItemCreating method, implement the same snippet from above.
Hope this helps!
I need to handle double click for QSplitter when cursor is under splitter.
I redefined mouseDoubleClickEvent. But this does not work for this case.
When I do doulble click when cursor is under splitter (ready to move splitter) the method is not calling.
You can use an event filter to filter all events going to the handle of Qsplitter :
bool MyClass::eventFilter(QObject * obj, QEvent * event)
{
if(event->type()==QEvent::MouseButtonDblClick)
{
...
}
return false;
}
Also don't forget to install event filter in the constructor of your class :
MyClass::MyClass(QWidget *parent):QWidget(parent)
{
...
ui->splitter->handle(1)->installEventFilter(this);
...
}
I needed the same in order to be able to evenly space the widgets in the splitter when the user double clicks on the handle (this was my use case). Overriding QSplitter.mouseDoubleClickEvent() does not work because it seems that the handle consumes the double click event itself so it is not propagated to the parent QSplitter. The solution proposed in the accepted answer using eventFilter is quite good but is has the disadvantage that it is not 'dynamic', i.e. the event filter is not installed when the user adds new widgets to the splitter during runtime. So we need to find a way to install the event filter dynamically. There are two options to achieve this:
Override QSplitter.addWidget() and QSplitter.insertWidget():
# inside class MySplitter
def addWidget(self, widget):
super(MySplitter, self).addWidget(widget) # call the base class
self.handle(self.count() - 1).installEventFilter(self)
def insertWidget(self, index, widget):
super(MySplitter, self).insertWidget(index, widget) # call the base class
self.handle(index).installEventFilter(self)
but this is a bit problematic when the user adds widgets by not using these two methods but by setting parent to the child widget, though this is discouraged by the docs - see: http://doc.qt.io/qt-5/qsplitter.html#childEvent
Intercept the childEvent(), which feels a bit hacky but is error proof:
# inside class MySplitter
def childEvent(self, event):
if event.added():
# Note that we cannot test isinstance(event.child(), QSplitterHandle)
# because at this moment the child is of type QWidget,
# it is not fully constructed yet.
# So we assume (hacky but it works) that the splitter
# handle is added always as the second child after
# the true child widget.
if len(self.children()) % 2 == 0:
event.child().installEventFilter(self)
super(MySplitter, self).childEvent(event) # call the base class
I am using b) and it works for me quite well. This has the advantage that you do not need to subclass (I do, however, for teh sake of simplicity), you can install another event filter to intercept the childEvent and install the event filter from outside.
Sorry my code is in PyQt, but I think it is idiomatic enough and easily translated to C++.
I have a list extending Ext.dataview.List.
I would like to play an animation in only one of the list items.
If it is triggered by the itemTap, it is easy, because the callback provides a third argument, I just run the animation on it. (I mean Ext.Anim.run).
But what if I need to animate the n-th element independently from the list, like triggered by a user tap on a separate button?
Thanks
Let's say you have a list which has the following config :
xtype:'list',
cls: 'myList',
...
Then you can access its DOM element with :
var items = Ext.DomQuery.select('.myList .x-list-item');
It will returns all the items of the list with the cls 'myList' so be sure to have only one list with this class.
From there you can do whatever you want with it like hiding the second item :
items[1].style.display = 'none';
Hope this helped