Package ej.widget.container

Class Grid

  • public class Grid
extends Container
    Lays out any number of children in a grid.

    All the children are laid out in a grid, which has a fixed number of columns if the grid is horizontal, or a fixed number of rows if the grid is vertical.

    In a grid, all children have the same width and the same height, regardless of their optimal size.

    Horizontal:

    Horizontal grid.

    Vertical:

    Vertical grid.

    • Constructor Detail

      • Grid

        public Grid​(boolean orientation,
            int count)
        Creates a grid specifying its orientation and the number of widgets per row/column (depending on the orientation chosen via the horizontal parameter).
        Parameters:
        orientation - the orientation of the grid (see LayoutOrientation).
        count - the number of widgets per row/column to set.
        Throws:
        IllegalArgumentException - if the count is negative or zero.

    • Method Detail

      • setOrientation

        public void setOrientation​(boolean orientation)
        Sets the orientation of this grid.
        Parameters:
        orientation - the orientation to set (see LayoutOrientation).

      • getOrientation

        public boolean getOrientation()
        Gets the orientation of this grid.
        Returns:
        the orientation of this grid (see LayoutOrientation).

      • setCount

        public void setCount​(int count)
        Sets the number of widgets per row/column (depending on the grid orientation).
        Parameters:
        count - the number of widgets per row/column to set.
        Throws:
        IllegalArgumentException - if the count is negative or zero.

      • getCount

        public int getCount()
        Gets the number of widgets per row/column (depending on the grid orientation).
        Returns:
        the number of widgets per row/column.

      • getCellChild

        public Widget getCellChild​(int column,
                           int row)
        Gets the widget at the specified column and row.
        Parameters:
        column - the column of the widget to return.
        row - the row of the widget to return.
        Returns:
        the widget at the specified column and row.
        Throws:
        IndexOutOfBoundsException - if the cell referenced by the given coordinates is out of range.

      • addChild

        public void addChild​(Widget child)
        Description copied from class: Container
        Adds the specified widget to the end of the list of children of this container.

        The container needs to be laid out again.

        Should be called in the display thread to avoid concurrency issues.

        Overrides:
        addChild in class Container
        Parameters:
        child - the widget to add.
        See Also:
        Widget.requestLayOut(), Widget.isAttached()

      • removeChild

        public void removeChild​(Widget child)
        Description copied from class: Container
        Removes the specified widget from the list of children of this container.

        The container needs to be laid out again.

        If the widget is not in the list of children of the container, nothing is done.

        Should be called in the display thread to avoid concurrency issues.

        Overrides:
        removeChild in class Container
        Parameters:
        child - the widget to remove.
        See Also:
        Widget.requestLayOut()

      • insertChild

        public void insertChild​(Widget child,
                        int index)
        Description copied from class: Container
        Inserts the specified widget at the specified index in the list of children of this container.

        The container needs to be laid out again.

        Should be called in the display thread to avoid concurrency issues.

        Overrides:
        insertChild in class Container
        Parameters:
        child - the widget to add.
        index - the index at which the widget should be inserted.
        See Also:
        Widget.requestLayOut(), Widget.isAttached()

      • replaceChild

        public void replaceChild​(int index,
                         Widget child)
        Description copied from class: Container
        Replaces the child at the specified index in the list of children of this container by the specified widget.

        If the specified widget is already the child at the specified index of the list of children, nothing is done.

        The container needs to be laid out again.

        Should be called in the display thread to avoid concurrency issues.

        Overrides:
        replaceChild in class Container
        Parameters:
        index - the index of the child to replace.
        child - the widget to add.
        See Also:
        Widget.requestLayOut(), Widget.isAttached()

      • removeAllChildren

        public void removeAllChildren()
        Description copied from class: Container
        Removes all the children of this container.

        The container needs to be laid out again.

        Should be called in the display thread to avoid concurrency issues.

        Overrides:
        removeAllChildren in class Container
        See Also:
        Widget.requestLayOut()

      • computeContentOptimalSize

        protected void computeContentOptimalSize​(Size size)
        Description copied from class: Widget
        Computes the optimal size of the widget.

        This method does not consider the border, margin, padding and dimension specified in the style.

        The given size is the available size for this widget in its parent. A width or a height equal to Widget#NO_CONSTRAINT means that there is no constraint on this dimension.

        The given size is modified to set the optimal size.

        Specified by:
        computeContentOptimalSize in class Widget
        Parameters:
        size - the size available for the content.

      • layOutChildren

        protected void layOutChildren​(int contentWidth,
                              int contentHeight)
        Description copied from class: Container
        Lays out the children of this container.

        The given size is the size of this container minus the border, margin and padding specified in the style.

        When this method returns the children of this container have been lay out using Container.layOutChild(Widget, int, int, int, int).

        Specified by:
        layOutChildren in class Container
        Parameters:
        contentWidth - the width available for the content.
        contentHeight - the height available for the content.