SplitPane class

A widget that divides a viewport into two side-by-side or stacked children.

The two child widgets are separated by an interactive divider bar.

Resizing Behavior via Divider Dragging

  • When a mouse press occurs on the divider's cell coordinates, the widget enters dragging mode.
  • During a mouse drag event, the split pane recalculates the divider position based on the mouse coordinates.
  • It clamps the new position to respect the min/max limits of both children.
  • Finally, it dynamically mutates the constraints of child1 and child2 in place (e.g. updating a LengthConstraint or PercentageConstraint), causing the layout solver to adjust child viewports on subsequent frames.

Example Usage

SplitPane(
  direction: LayoutDirection.horizontal,
  dividerChar: '│',
  child1: LeftPanel(),
  constraint1: const LengthConstraint(20),
  child2: RightPanel(),
  constraint2: const FlexConstraint(1),
);

Properties and Settings

Property Type Description
child1 Widget The first child widget.
child2 Widget The second child widget.
constraint1 Constraint The layout constraint for child1.
constraint2 Constraint The layout constraint for child2.
direction LayoutDirection Split direction (horizontal or vertical).
dividerChar String The character character representing the divider line.
dividerStyle Style Rendering style attributes for the divider cells.
Inheritance

Constructors

SplitPane({required Widget child1, required Widget child2, required Constraint constraint1, required Constraint constraint2, LayoutDirection direction = LayoutDirection.horizontal, String dividerChar = '│', Style dividerStyle = Style.empty})
Creates a SplitPane widget.

Properties

child1 → Widget
The first child widget.
final
child2 → Widget
The second child widget.
final
constraint1 ↔ Constraint
The layout constraint for child1.
getter/setter pair
constraint2 ↔ Constraint
The layout constraint for child2.
getter/setter pair
direction → LayoutDirection
Split direction (horizontal or vertical).
final
dividerChar → String
The character representing the divider line.
final
dividerPosition → int
Gets the current divider position.
no setter
dividerStyle → Style
Rendering style attributes for the divider cells.
final
hashCode → int
The hash code for this object.
no setterinherited
key → Key?
The optional key for this widget.
finalinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

createElement() → Element
Creates an Element to manage this widget's location in the tree.
inherited
getIntrinsicHeight(int width) → int
Computes the intrinsic height of this widget under the given width constraint.
inherited
handleMouseEvent(MouseEvent event, int localX, int localY) → void
Intercepts mouse drag/press events over the divider.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
render(Buffer buffer, Rect area) → void
Renders the widget onto the provided buffer within the specified area.
override
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited