View

Base class for GUI components.

Modulerequire("gui")
TypeClass
InheritsResponder

View provides methods to receive and change various style properties.

Methods

offsetFromView(view)

Return offset from view.

Parameters

Return

Vector2dF

offsetFromWindow()

Return offset from the window that owns the view.

Return

Vector2dF

getBounds()

Return the position and size of the view, relative to its parent.

Return

RectF

getBoundsInScreen()

Return the position and size of the view in the screen.

Return

RectF

layout()

Make the view re-recalculate its layout.

schedulePaint()

Schedule to repaint the whole view.

schedulePaintRect(rect)

Schedule to repaint the rect area in view.

Parameters

setVisible(visible)

Show/Hide the view.

Parameters

isVisible()

Return whether the view is visible.

Return

Boolean

isVisibleInHierarchy()

Return whether the view and its ancestors are visible.

Return

Boolean

setEnabled(enable)

Set whether the view is enabled.

The enabled state of each view is not affected by its parent, disabling a container-like view does not have any effect.

Parameters

isEnabled()

Return whether the view is enabled.

Return

Boolean

focus()

Move the keyboard focus to the view.

hasFocus()

Return whether the view has keyboard focus.

Return

Boolean

setFocusable(focusable)

Set whether the view can be focused on.

Parameters

isFocusable()

Return whether the view can be focused on.

Return

Boolean

setMouseDownCanMoveWindow(can)

Set whether dragging mouse would move the window.

For most platforms this method only works for frameless windows, having this feature may also prevent mouse events to happen.

On macOS the Container view has this feature turned on by default. To turn this feature on for the view, the view's parent view must also has this feature turned on.

On Windows the view with this feature will be treated as titlebar, e.g. double-clicking would maximize the window, right-clicking may show the system menu.

Parameters

isMouseDownCanMoveWindow()

Return whether dragging the view would move the window.

Return

Boolean

doDrag(data, operations)

Like DoDragWithOptions but do not set drag image.

Parameters

Return

Integer

doDragWithOptions(data, operations, options)

Start a drag session.

The return value is a DragOperation indicating the result of dragging.

This method should only be called in the on_mouse_down event, when user starts to drag the cursor.

This method is blocking that it does not return until the drag session is finished or cancelled. During the call a nested UI message loop will run and other events will still be emitted.

Note that on macOS certain views may have IsMouseDownCanMoveWindow defaulting to true, which will prevent drag session to start. Make sure to call SetMouseDownCanMoveWindow(false) for drag sources.

Parameters

Return

Integer

cancelDrag()

Cancel current drag session if the view is being used as drag source.

isDragging()

Return whether the view is being used as drag source.

Return

Boolean

registerDraggedTypes(types)

Make the view a drag destination that accepets types.

Parameters

setCursor(cursor)

Set the cursor to show when hovering the view.

On Linux, setting cursor would force the view to own its own GDK window. For certain views like Label, this may have remove the view's background color.

Parameters

setTooltip(tooltip)

Set the tooltip for the view.

This method will clear all tooltips added by addTooltipForRect.

Parameters

addTooltipForRect(tooltip, rect)

Add tooltip for a defined rect in the view and return an ID for it.

Parameters

Return

Integer

removeTooltip(id)

Remove tooltip added by addTooltipForRect with id.

Parameters

setFont(font)

Change the font used for drawing text in the view.

This methods only works for Views that display text, like Label or Entry.

Parameters

setColor(color)

Change the color used for drawing text in the view.

This methods only works for Views that display text, like Label or Entry.

Parameters

setBackgroundColor(color)

Change the background color of the view.

Parameters

setStyle(styles)

Change the styles of the view.

Available style properties can be found at Layout System.

Parameters

getComputedLayout()

Return string representation of the view's layout.

Return

String

getMinimumSize()

Return the minimum size needed to show the view.

Return

SizeF

getParent()

Return parent view.

Return

View

getWindow()

Return the window that the view belongs to.

Return

Window

Events

onDragLeave(self, info)

Emitted when cursor leaves the view while dragging.

This event will also be emitted before the handle_drop event when user drops the data on the view.

Parameters

Preventable

No.

onSizeChanged(self)

Emitted when the view's size has been changed.

Parameters

Preventable

No.

onFocusIn(self)

Emitted when the view gets keyboard focus.

Parameters

Preventable

Yes.

onFocusOut(self)

Emitted when the view loses keyboard focus.

Parameters

Preventable

Yes.

Delegates

handleDragEnter(self, info, point)

Called when user drags the cursor over the view for the first time.

A DragOperation should be returned, indicating which dragging operation the destination will perform when cursor is released.

This delegate will not be called if the view has not registered dragged types, or if the dragged data does not belong to the registered type.

On Linux the dragged data is not yet available when this is called, you should usually only read data in the handle_drop delegate.

Parameters

Return

Integer

handleDragUpdate(self, info, point)

Called when user moves the cursor over the view while dragging.

A DragOperation should be returned, indicating which dragging operation the destination will perform when cursor is released.

If this delegate is not implemented, the return value of previous handle_drag_enter call will be returned.

This delegate is usually used when implementing a custom view with multiple dropping areas, you only need to implement handle_drag_enter for simple tasks.

On Linux the dragged data is not yet available when this is called, you should usually only read data in the handle_drop delegate.

Parameters

Return

Integer

handleDrop(self, info, point)

Called when user releases the dragged data on the view.

Returning true will inform the drag source that the data has been accepted with the drag operation returned by previous handle_drag_enter or handle_drag_update call.

If the drag operation is Move, the drag source may also take actions to "remove" the data on its side.

Returning false will inform the drag source that the drag has been cancelled, and operating system may display some visual effects.

Parameters

Return

Boolean