PickerView Events
The PickerView widget has the following event associated with it:
This event is invoked for every widget when the widget position and dimensions are computed. This event is invoked for all the widgets placed inside flex containers. This event is invoked in the order in which the widgets are added to the widget hierarchy and expect the frame property of the widget is calculated and available for use within this event.
This event is used to set the layout properties of child widgets in the relation to self and peer widgets whose layout is not yet performed.
Syntax
doLayout()
Read/Write
Yes - (Read and Write)
Remarks
Note: The number of times this event invoked may vary per platform. It is not recommended to write business logic assuming that this function is invoked only once when there is a change in positional or dimensional properties. This event will not trigger when transformations are applied though widget is moved or scaled or rotated from its original location.
Example
//Sample code to set doLayout event callback to a button widget.
/*This code changes the top property of button2 and makes it appear below button1.*/
myForm.button1.doLayout=doLayoutButton1;
function doLayoutButton1(){
myForm.button2.top = myForm.button1.frame.height;
}Platform Availability
- iOS
- Android
- Windows
- SPA
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);
LabelWdg.onScrollWidgetPosition = onScrollWidgetPositionCallBack;
function onScrollWidgetPositionCallBack(wdg, screenX, screenY, frameX, frameY) { //wdg : Widget that is registered for onScrollWidgetPosition.
/*screenX : Position of widget with respect to
the screen's X - coordinates (after downsizing the navigation bar and status bar).*/
/*screenY : Position of widget with respect to the screen's Y -
coordinates (after downsizing the navigation bar and status bar).*/
//frameX : Position of widget with respect to parent container's X- coordinates.
//frameY : Position of widget with respect to parent container's Y- coordinates.
}Platform Availability
- Not Accessible from IDE
- Android, iOS, SPA, and Windows
An event callback that is invoked by the platform when the component selection changes.
Syntax
onSelection()
Parameters
pickerViewRef [widgetref]
Optional
Handle to the widget instance.
component [Number]
Optional
Specifies the component of the pickerview.
keySelected [String ]
Optional
Specifies the selected key of the component.
Return Values
None
Read/Write
Yes - (Read and Write)
Example
//Sample code to set the onSelection event callback to a PickerView widget.
frmPView.myPView.onSelection=onSelectionCallBack;
function onSelectionCallBack(picker){
//Write your logic here.
}Accessible from IDE
Yes
Platform Availability
Available on all platforms except SPA.
An event callback is invoked by the platform when the user touch is released from the touch surface.
Syntax
onTouchEnd ()
Optional Parameters
source
Handle to the widget reference on which the user touch has ended.
x
Specifies the x-coordinate with in the widget with respect to widget’s co-ordinate system. It is a number indicating device independent pixel.
y
Specifies the y- coordinate with in the widget with respect to widget’s co-ordinate system. It is a number indicating device independent pixel.
contextInfo
On devices that support 3D Touch, specifies a key-value pair where the value specifies the force of the touch. The value 1.0 represents the force of an average touch, as determined by the system.
Note: 3D Touch is available only on iOS 9.0 and later.
Read/Write
Read + Write
Remarks
This event is invoked asynchronously.
Example
function onTouchEndCallback(source, x, y, contextInfo) {
if (contextInfo) {
var force = contextInfo[“force”];
voltmx.print(“value of force is” + force)
}
}
Form1.widget1.onTouchEnd = onTouchEndCallback;Platform Availability
- iOS, Android, Windows, and SPA
An event callback is invoked by the platform when the touch moves on the touch surface continuously until movement ends.
Syntax
onTouchMove ()
Optional Parameters
source
Handle to the widget reference on which touch moves.
x
Specifies the x-coordinate with in the widget with respect to widget’s co-ordinate system. It is a number indicating device independent pixel.
y
Specifies the y- coordinate with in the widget with respect to widget’s co-ordinate system. It is a number indicating device independent pixel.
contextInfo
On devices that support 3D Touch, specifies a key-value pair where the value specifies the force of the touch. The value 1.0 represents the force of an average touch, as determined by the system.
Note: 3D Touch is available only on iOS 9.0 and later.
Read/Write
Read + Write
Remarks
This event is invoked asynchronously.
Example
function onTouchMoveCallback(source, x, y, contextInfo) {
if (contextInfo) {
var force = contextInfo[“force”];
voltmx.print(“value of force is” + force)
}
Form1.widget1.onTouchMove = onTouchMoveCallback; Platform Availability
- iOS, Android, Windows, and SPA
An event callback is invoked by the platform when the user touches the touch surface.
Syntax
onTouchStart ()
Optional Parameters
source
Handle to the widget reference on which the user touches.
x
Specifies the X co-ordinate with in the widget with respect to widget’s co-ordinate system. It is a number indicating device independent pixel.
y
Specifies the Y co-ordinate with in the widget with respect to widget’s co-ordinate system. It is a number indicating device independent pixel.
contextInfo
On devices that support 3D Touch, specifies a key-value pair where the value specifies the force of the touch. The value 1.0 represents the force of an average touch, as determined by the system.
Note: 3D Touch is available only on iOS 9.0 and later.
Read/Write
Read + Write
Remarks
This event is invoked asynchronously.
Example
function onTouchStartCallback(source, x, y, contextInfo) {
if (contextInfo) {
var force = contextInfo[“force”];
voltmx.print(“value of force is” + force)
}
}
Form1.widget1.onTouchStart = onTouchStartCallback; Platform Availability
- iOS, Android, Windows, and SPA