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1.156 class tab

A tab object is a refinement of a dialog_group object, which implies it is a device specialised for displaying dialog_item objects.

A tab shows its name as a label above a flat rounded box with its contents. Tabs are designed to cooperate in a tab_stack object, to achieve a stack of sheets holding controllers, which allows the user to switch by clicking the desired tab.

Tabs are normally used to establish settings for a system that has many settings. Groups of related settings will be placed on a separate tab.

Each label is a pill: a box with a half circle at each end. The label of the tab on top has an edge in the accent colour. The labels of the hidden tabs have their background moved a little towards the text colour and dimmed text. This works for light and dark themes alike. The box around the contents is drawn in the class variable border_colour.

See also class tab_stack.

1.156.1 Class variables

tab.indicator_colour: colour* = ui_accent
Colour of the edge of the label of the tab on top. @nil omits the edge.
tab.indicator_width: 0.. = 2
Width of this edge. 0 omits the edge.

1.156.2 Instance variables

tab <- icon: image*
Image shown left of the text of the label, scaled to the height of the text. It sits in the half circle at the left end of the label, as a close button (see tab<-closable) sits in the one at the right end. It is dimmed with the label of a hidden tab. Default @nil.
tab <- label_format: {left,center,right}
Deternines how the label is aligned the box.
tab <- label_offset: int
Distance from the left-side of the object to the left-side of the label-box. Normally set by tab_stack->layout_labels.
tab <- label_size: size
Size of the label-box. If the text does not fit the size of the box, it will automatically be enlarged.
tab <- status: {on_top,hidden}
A tab object can be in tab<-status: on_top, in which case it will display both the label and the contents. Otherwise it will only display the label.

1.156.3 Send methods

tab ->event: event
If the event occurred in the label-area of the tab, invoke tab->label_event. Otherwise if the tab is top-most (see tab_stack->on_top and tab<-status) process the event on the content of the tab. See dialog_group->event.
tab ->flash: area=[area], time=[num]
If the tab<-status is on_top, the drawing area of the tab is inverted, otherwise the tag is inverted. See also graphical->flash.
tab ->initialise: name=[name]
Create a tab object with the given name. A tab is a subclass of class dialog_group and allows for displaying dialog_item objects. A tab must be added to a stack using the method tab_stack->append or using tab_stack->initialise.
tab ->label_event: event
Process event object that occurred on label. Default is to make the receiving tab the topmost (see tab_stack->on_top) on receiving an ms_left_down event. This method may be refined -for example- to attach a popup object to the tab. See also tab->event and graphical->event.
tab ->x: int
Left-side of tab.
tab ->y: int
Top-side of tab.
tab ->position: point
Determines the top-left corner of the tab, while the origin of the tab, regarded as a device object is the top-level of the rectangle used for displaying the contents.

1.156.4 Get methods

tab <-label_area: area ->
The box (pill) of the label, relative to the area of the tab. Fails if the label is not shown.
tab <-position: -> point
Inherits description from: tab->position
tab <-x: -> int
Determines the top-left corner of the tab, while the origin of the tab, regarded as a device object is the top-level of the rectangle used for displaying the contents.

Inherits description from: tab->position

tab <-y: -> int
Determines the top-left corner of the tab, while the origin of the tab, regarded as a device object is the top-level of the rectangle used for displaying the contents.

Inherits description from: tab->position