.CollectionView Events
The CollectionView widget has the following events associated with it:
onDecelerationStarted Event
This event is triggered only on iOS. It is called when deceleration starts at the end of scrolling.
Syntax
onDecelerationStarted()
Read/Write
Read + Write
Remarks
This event is supported only on iOS
Example
//Sample code to set onDecelerationStarted event callback for CollectionView widget.
frmCollection.myCollection.onDecelerationStarted=deceleratedCallback;
function deceleratedCallback(){
//Write your code here.
}
Platform Availability
- iOS
onItemDisplay Event
This event is triggered when you display any item in the CollectionView widget.
Syntax
onItemDisplay(
widgetHandle,
sectionIndex,
itemIndex,
itemMdl)
Parameters
widgetHandle
Specifies the current CollectionView widget.
sectionIndex
Specifies the index of the section of CollectionView item
itemIndex
Specifies the index of the clicked item.
itemMdl
Specifies the item Model corresponding to the section index and item index. This parameter is valid only for iOS and SPA platforms.
Read/Write
Read + Write
Remarks
The onItemDisplay event provides you access to the itemMdl. This itemMdl can be animated by using the itemMdl.animate API. For more information on widget animation, refer the Widget Animation Using Flex Forms section.
Example
function onItemDisplay(widgetHandle, sectionIndex, itemIndex, itemMdl) {
voltmx.print("widgetHandle is:" + widgetHandle);
voltmx.print("sectionIndex is:" + sectionIndex);
voltmx.print("itemIndex is:" + itemIndex);
voltmx.print("itemMdl is:" + itemMdl);
}
Platform Availability
Available on all platforms.
onItemSelect Event
This event is triggered when the user selects any item in the CollectionView.
Syntax
onItemSelect (
Widget,
sectionIndex,
ItemIndex)
Parameters
CollectionViewWidget
Reference to the CollectionView widget that raised the event.
SectionIndex
Specifies the index of the section to which the item belongs to.
ItemIndex
Specifies the index of item that has been clicked.
Read/Write
Read + Write
Remarks
This event is not raised if the selectable property in the metainfo is set to false.
In the Android platform, when a gesture or touch events are placed inside the flex template for the CollectionView widget, because of the propagation of events to the below container, the flex template may not receive the onItemSelect event.
Platform Availability
- iOS
- Android
- Windows
- SPA
onPull Event
An event callback that is invoked by the platform when scrolling the CollectionView widget from it's edges.
Syntax
onPull(JSFlexContainer)
Parameters
JSFlexContainer
Handle to the widget reference.
Read/Write
Read + Write
Remarks
For flow layout:
- The views created from these widgets are shown when you pull or push the scrollview container from its edges.
For horizontal layout:
- The width of the view is set to the width of the CollectionView.
- The height is based on the height configured for the CollectionView Widget. 50dp is the default value.
- The view is docked at the extreme end of the CollectionView widget.
For vertical layout:
- The height of the view is set to the height of the CollectionView.
- The view is docked at the extreme end of the CollectionView widget.
Example
//Sample code to set onPull event callback for CollectionView widget.
frmCollection.myCollection.onPull=onPulleventCallback;
function onPulleventCallback(widgetref){
voltmx.print("widget reference:" + widgetref);
}
Platform Availability
- iOS
- Android
- Windows
- SPA
onPush Event
An event callback that is invoked by the platform when scrolling the CollectionView widget widget from it's edges.
Syntax
onPush(widgetref)
Parameters
widgetref
Handle to the widget reference.
Read/Write
Read + Write
Remarks
For flow layout:
- The views created from these widgets are shown when you pull or push the FlexContainer from its edges.
For horizontal layout:
- The width of the view is set to the width of the CollectionView.
- The height is based on the height configured for the CollectionView Widget. 50dp is the default value.
- The view is docked at the extreme end of the CollectionView widget.
For vertical layout:
- The height of the view is set to the height of the CollectionView.
- The view is docked at the extreme end of the CollectionView widget.
Example
//Sample code to set onPush event callback for CollectionView widget.
frmCollection.myCollection.onPush=onPusheventCallback;
function onPusheventCallback(widgetref){
voltmx.print("widget reference:" + widgetref);
}
Platform Availability
- iOS
- Android
- Windows
- SPA
onReachingBegining Event
onReachingBegining gets called when scrolling reaches the beginning of the CollectionView widget.
Syntax
onReachingBegining(CollectionViewWidget,offset)
Parameters
CollectionViewWidget
Handle to the widget reference.
offset
Object containing values for x and y.
Read/Write
Read + Write
Example
//Sample code to set onReachingBegining event callback for CollectionView widget.
frmCollection.myCollection.onReachingBegining=onReachingBeginingCallback;
function onReachingBeginingCallback(widgetref, offset){
voltmx.print("widget reference:" + widgetref + "and the offset is:" + offset);
}
Platform Availability
- iOS
- Android
- Windows
- SPA
onReachingEnd Event
onReachingEnd gets called when scrolling reaches the end of the CollectionView widget.
Syntax
onReachingEnd(CollectionViewWidget)
Parameters
CollectionViewWidget
Handle to the widget reference.
offset
Object containing values for x and y.
Read/Write
Read + Write
Example
//Sample code to set onReachingEnd event callback for CollectionView widget.
frmCollection.myCollection.onReachingEnd=onReachingEndCallback;
function onReachingEndCallback(widgetref, offset){
voltmx.print("widget reference:" + widgetref + "and the offset is:" + offset);
}
Platform Availability
- iOS
- Android
- Windows
- SPA
onScrollStart Event
Indicates that the scroll container inside the CollectionView widget started scrolling.
Syntax
onScrollStart (source)
Parameters
source
Specifies the widget on which scrolling started.
Read/Write
Read + Write
Remarks
The onScrollStart event is called asynchronously. The event is triggered only when scrolling is started. When touch does not result to a scroll, this event is not raised.
Example
//Sample code to set onScrollStart event callback for CollectionView widget.
frmCollection.myCollection.onScrollStart =onScrollStartCallback;
function onScrollStartCallback(eventobject){
voltmx.print("eventobject is:" + eventobject);
}
Platform Availability
- iOS
- Android
- Windows
- SPA
onScrollTouchReleased Event
Indicates that user scrolling touch on the display is released. This callback is called asynchronously.
Syntax
onScrollTouchReleased (source)
Parameters
source
Specify the segment on which scrolling touch is released.
Read/Write
Read + Write
Example
//Sample code to set onScrollTouchReleased event callback for CollectionView widget.
frmCollection.myCollection.onScrollTouchReleased=onScrollTouchReleasedCallback;
function onScrollTouchReleasedCallback(eventobject){
voltmx.print("eventobject is:" + eventobject);
}
Platform Availability
- iOS
- Android
- Windows
- SPA
onScrolling Event
Indicates that segment scrolling is in progress. This callback is called asynchronously.
Syntax
onScrolling (source)
Parameters
source
Specify the segment on which scrolling is in progress.
Read/Write
Read + Write
Example
//Sample code to set onScrolling event callback for CollectionView widget.
frmCollection.myCollection.onScrolling=onScrollingCallback;
function onScrollingCallback(eventobject){
voltmx.print("eventobject is:" + eventobject);
}
Platform Availability
- iOS
- Android
- Windows
- SPA
onScrollEnd Event
Indicates that segment scrolling has come to an end.
Syntax
onScrollEnd (source)
Parameters
source
Specify the segment on which scrolling is coming to an end.
Read/Write
Read + Write
Remarks
The onScrollEnd callback is called asynchronously. This event is called only when the scrolling reached end of the scroll.
When multiple scrolls performed on the Segment widget, the onScrollTouchReleased is triggered whenever touch is released, but the onScrollEnd event is triggered only when the entire scrolling is ended. So when the user keeps on flinging on the display, the onScrollTouccReleased callback is triggered multiple times and onScrollEnd is triggered only once.
Example
//Sample code to set onScrollEnd event callback for CollectionView widget.
frmCollection.myCollection.onScrollEnd=onScrollEndCallback;
function onScrollEndCallback(eventobject){
voltmx.print("eventobject is:" + eventobject);
}
Platform Availability
- iOS
- Android
- Windows
- SPA
onScrollWidgetPosition Event
This event callback is invoked by the platform when the widget location position gets changed on scrolling. The onScrollWidgetPosition event returns the positional coordinates of the widget's location with respect to the screen (screenX and screenY) and the parent container (frameX and frameY). This event is invoked asynchronously, and is not available for FlexForm widget.
Syntax
onScrollWidgetPosition()
Read/Write
Read + Write
Example
var LabelWdg = new voltmx.ui.Label(basicConf, layoutConf, pspConf);
form.add(LabelWdg);
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