Class GridLayout

java.lang.Object

vaadinx.awt.GridLayout

All Implemented Interfaces:

Serializable, CssEmittingLayoutManager, LayoutManager

public class GridLayout
extends Object
implements CssEmittingLayoutManager, Serializable

Emulator for GridLayout (D_gridlayout). Under D_layout_css_on_content, CssEmittingLayoutManager.layoutContainer(Container) writes display: grid; grid-template-columns: repeat(ncols, 1fr); grid-template-rows: repeat(nrows, 1fr); gap: … to the container's peer content element via EHelper.applyContainerCss(Element, String, Map).

Hand-written rather than generator-emitted: the generator's root-class detection assumes Component-hierarchy ancestry and would emit a peer field, which a LayoutManager doesn't have. Plain LayoutManager (not LayoutManager2) — JDK GridLayout has no per-child constraint storage; cell assignment is purely insertion-order driven, which the browser's grid auto-placement (row-major, the CSS default) reproduces exactly.

Dimension resolution. JDK GridLayout fixes one dimension and derives the other from the live component count: with rows > 0 the row count is authoritative and columns are ceil(n / rows); with rows == 0 columns are authoritative and rows are ceil(n / cols). That count isn't known until layout time, so — unlike the constraint-carrying GridBagLayout — this layout reads Container.getComponentCount() inside CssEmittingLayoutManager.layoutContainer(Container) and computes the resolved dimensions there, exactly as JDK's layoutContainer does.

Cell sizing (R_layouts_close_enough). Every cell is an equal fraction (1fr) and every child stretches to fill it (align/justify-items: stretch) — matching GridLayout's "all cells equal, components resized to fill" contract. We do not compute the pixel arithmetic JDK does from child preferred sizes; the browser divides the container evenly, which is close-enough per R_layouts_close_enough. hgap/vgap carry through to CSS gap.

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
GridLayout()	JDK: GridLayout() → one row, columns derived from child count.
GridLayout(int rows, int cols)
GridLayout(int rows, int cols, int hgap, int vgap)

Method Summary

Modifier and Type	Method	Description
void	addLayoutComponent(String name, Component comp)
Map<String,String>	childCss(Container parent, Component child)	Per-child CSS for one child of parent; null (the default) means the child needs none.
Map<String,String>	containerCss(Container parent)	Container-wide CSS for parent's peer content element (its <div>).
int	getColumns()
int	getHgap()
int	getRows()
int	getVgap()
Dimension	minimumLayoutSize(Container parent)
Dimension	preferredLayoutSize(Container parent)
void	removeLayoutComponent(Component comp)
void	setColumns(int cols)
void	setHgap(int hgap)
void	setRows(int rows)
void	setVgap(int vgap)
String	toString()

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface CssEmittingLayoutManager

cssLayoutName, layoutContainer

Constructor Details

GridLayout

public GridLayout()

JDK: GridLayout() → one row, columns derived from child count.

GridLayout

public GridLayout(int rows,
 int cols)

GridLayout

public GridLayout(int rows,
 int cols,
 int hgap,
 int vgap)

Method Details

getRows

public int getRows()

setRows

public void setRows(int rows)

getColumns

public int getColumns()

setColumns

public void setColumns(int cols)

getHgap

public int getHgap()

setHgap

public void setHgap(int hgap)

getVgap

public int getVgap()

setVgap

public void setVgap(int vgap)

addLayoutComponent

public void addLayoutComponent(String name,
 Component comp)

Specified by:

addLayoutComponent in interface LayoutManager

removeLayoutComponent

public void removeLayoutComponent(Component comp)

Specified by:

removeLayoutComponent in interface LayoutManager

preferredLayoutSize

public Dimension preferredLayoutSize(Container parent)

Specified by:

preferredLayoutSize in interface LayoutManager

minimumLayoutSize

public Dimension minimumLayoutSize(Container parent)

Specified by:

minimumLayoutSize in interface LayoutManager

childCss

public Map<String,String> childCss(Container parent,
 Component child)

Description copied from interface: CssEmittingLayoutManager

Per-child CSS for one child of parent; null (the default) means the child needs none. Called once per child per pass, after CssEmittingLayoutManager.containerCss(Container) (see the call-order contract).

Specified by:

childCss in interface CssEmittingLayoutManager

containerCss

public Map<String,String> containerCss(Container parent)

Description copied from interface: CssEmittingLayoutManager

Container-wide CSS for parent's peer content element (its <div>).

Specified by:

containerCss in interface CssEmittingLayoutManager

Returns:

property→value map; a null value removes the property, an absent key is left untouched.

toString

public String toString()

Overrides:

toString in class Object