Positioners

Table of contents

• ACenter
• HCenter
• VCenter
• AStrech
• HStretch
• VStretch
• HAnchor
• VAnchor
• AAnchor

Positioners are special tags that can be applied to a widget type which overwrite the geometry of the given widget when the output file is written. All other attributes of the widget are defined as normal and not touched by the positioner.

When defining the widget you want to position, just prepend with widget’s type with the positioner’s type. So if you have a Text widget, which is normally indicated with the ‘!Text’ type, and you want to horizontally center it within its parent, you would change that type to ‘!hcenter:Text’.

ACenter

Positions a widget so that the midpoint of the widget matches up with the midpoint of the widget’s parent. Note that, a parent’s size is determined at the point when a widget is defined. Any widgets defined afterward may affect the final size of the parent.

• Example

MidPointGroup: !acenter:group    
    children:
        - !TextMontor
            geometry: 50x20
            foreground: *alarm_yellow
            background: *transparent
            alignment: CenterRight
            pv: "S:SRcurrentAI"
            
        - !Text
            geometry: 55x0 x 25x20
            foreground: *alarm_yellow
            alignment: CenterLeft
            text: "mA"

HCenter

Positions a widget so that the midpoint of the widget on the horizontal axis matches up with the midpoint of the widget’s parent on the same axis. Note that, a parent’s size is determined at the point when a widget is defined. Any widgets defined afterward may affect the final size of the parent.

• Example

OPSElements: !hcenter:group
    geometry: 0x7 x 0x0
    
    children:
        - !TextMontor
            geometry: 50x20
            foreground: *alarm_yellow
            background: *transparent
            alignment: CenterRight
            pv: "S:SRcurrentAI"
            
        - !Text
            geometry: 55x0 x 25x20
            foreground: *alarm_yellow
            alignment: CenterLeft
            text: "mA"

VCenter

Positions a widget so that the midpoint of the widget on the vertical axis matches up with the midpoint of the widget’s parent on the same axis. Note that, a parent’s size is determined at the point when a widget is defined. Any widgets defined afterward may affect the final size of the parent.

You may also use the alias “center” to reference the vcenter node.

• Example

OPSElements: !vcenter:group
    geometry: 7x0 x 0x0
    
    children:
        - !TextMonitor
            geometry: 0x0 x 50x20
            foreground: *alarm_yellow
            background: *transparent
            alignment: CenterRight
            pv: "S:SRcurrentAI"
            
        - !Text
            geometry: 55x0 x 25x20
            foreground: *alarm_yellow
            alignment: CenterLeft
            text: "mA"

AStrech

Determines a widget’s width and height to match up respectively with the widget’s parent values. Note that, a parent’s size is determined at the point when a widget is defined. Any widgets defined afterward may affect the final size of the parent.

• Example

Fill_Parent: !astretch:Text            
    text: "Middle"
    alignment: CenterLeft

HStretch

Determines a widget’s width to match up with the size of the widget’s parent width. Note that, a parent’s size is determined at the point when a widget is defined. Any widgets defined afterward may affect the final size of the parent.

• Example

UITitle: !hstretch:Text
    geometry: 0x32
            
    text: "Middle"
    alignment: CenterLeft

VStretch

Determines a widget’s width to match up with the size of the widget’s parent width. Note that, a parent’s size is determined at the point when a widget is defined. Any widgets defined afterward may affect the final size of the parent.

You may also use the alias “stretch” to reference the vstretch node.

• Example

UITitle: !vstretch:Text
    geometry: 32x0
            
    text: "Middle"
    alignment: CenterLeft

HAnchor

Positions a widget at the horizontal extent of its parent node.

Note that, a parent’s size is determined at the point when a widget is defined. Any widgets defined afterward may affect the final size of the parent.

• Example

WideGroup: !Group
    geometry: 400x20
    children:
        - !HAnchor:Text
            geometry: 50x20
            text: "I'm at the end"

VAnchor

Positions a widget at the vertical extent of its parent node.

Note that, a parent’s size is determined at the point when a widget is defined. Any widgets defined afterward may affect the final size of the parent.

You may also use the alias “anchor” to reference the vachor node.

• Example

TallGroup: !Group
    geometry: 40x200
    children:
        - !HAnchor:Text
            geometry: 50x20
            text: "I'm at the bottom"

AAnchor

Positions a widget to be in the lower right corner of its parent node.

Note that, a parent’s size is determined at the point when a widget is defined. Any widgets defined afterward may affect the final size of the parent.

• Example

BigGroup: !Group
    geometry: 400x400
    children:
        - !HAnchor:Text
            geometry: 50x20
            text: "I'm in the corner"