Widgets StackPanelWidget

StackPanelWidget

StackPanelWidget is a lightweight layout container that arranges child widgets sequentially in a vertical or horizontal line.

Use it for option groups, button rows, toolbar-like groups, vertical menus that are not using the menu subsystem, and other simple code-first layouts.

These examples assume you already have a RenderSurfaceHostBase named host and, where appropriate, a View named view, a SceneLayer named sceneLayer, or a Sprite named sprite.

Vertical stack

using System.Drawing;
using Gondwana.Drawing.Direct;
using Gondwana.Widgets.Controls;
using Gondwana.Widgets.Layout;

var stack = new StackPanelWidget(
    host,
    DirectDrawingMode.View,
    anchor: new PointF(40, 40),
    orientation: WidgetOrientation.Vertical,
    spacing: 8f);

stack
    .AddWidget(new ButtonWidget(
        host, view, new Rectangle(0, 0, 200, 38), "New Game"))
    .AddWidget(new ButtonWidget(
        host, view, new Rectangle(0, 0, 200, 38), "Options"))
    .AddWidget(new ButtonWidget(
        host, view, new Rectangle(0, 0, 200, 38), "Quit"));

The stack determines child offsets from their sizes; the original absolute positions are not used as spacing between children.

Horizontal stack

stack.Orientation = WidgetOrientation.Horizontal;
stack.Spacing = 12f;
stack.Relayout();

Changing Orientation or Spacing automatically recalculates layout; calling Relayout() explicitly is useful after changing child sizes.

Content size

SizeF size = stack.ContentSize;

ContentSize reports the current laid-out dimensions of all children including spacing.

Removing a child

stack.RemoveWidget(optionsButton, dispose: false);

Drawing mode

The constructor accepts DirectDrawingMode.View or DirectDrawingMode.SceneLayer. The first child establishes the actual view or scene-layer target used by the container.

Do not mix view-level and scene-layer widgets in the same stack.

Useful members

Member	Purpose
Orientation	Horizontal or vertical layout.
Spacing	Pixels between adjacent children.
ContentSize	Current total laid-out size.
AddWidget()	Adds and lays out a child.
RemoveWidget()	Removes a child and recalculates layout.
Relayout()	Recomputes all child offsets.