info.clearthought.layout
Class TableLayout

java.lang.Object
  info.clearthought.layout.TableLayout

All Implemented Interfaces:

LayoutManager, LayoutManager2, Serializable, TableLayoutConstants

public class TableLayout

extends Object

implements LayoutManager2, Serializable, TableLayoutConstants

TableLayout is a layout manager that arranges components in rows and columns like a spreadsheet. TableLayout allows each row or column to be a different size. A row or column can be given an absolute size in pixels, a percentage of the available space, or it can grow and shrink to fill the remaining space after other rows and columns have been resized.

Using spreadsheet terminology, a cell is the intersection of a row and column. Cells have finite, non-negative sizes measured in pixels. The dimensions of a cell depend solely upon the dimensions of its row and column.

A component occupies a rectangular group of one or more cells. The component can be aligned in four ways within that cell.

A component can be stretched horizontally to fit the cell set (full justification), or it can be placed in the center of the cell. The component could also be left justified or right justified. Similarly, the component can be full, center, top, or bottom justified along the

 public static void main (String args[])
 {
     // Create a frame
     Frame frame = new Frame("Example of TableLayout");
     frame.setBounds (100, 100, 300, 300);
 
     // Create a TableLayout for the frame
     double border = 10;
     double size[][] =
         {{border, 0.10, 20, TableLayout.FILL, 20, 0.20, border},  // Columns
          {border, 0.20, 20, TableLayout.FILL, 20, 0.20, border}}; // Rows
 
     frame.setLayout (new TableLayout(size));
 
     // Create some buttons
     String label[] = {"Top", "Bottom", "Left", "Right", "Center", "Overlap"};
     Button button[] = new Button[label.length];
 
     for (int i = 0; i < label.length; i++)
         button[i] = new Button(label[i]);
 
     // Add buttons
     frame.add (button[0], "1, 1, 5, 1"); // Top
     frame.add (button[1], "1, 5, 5, 5"); // Bottom
     frame.add (button[2], "1, 3      "); // Left
     frame.add (button[3], "5, 3      "); // Right
     frame.add (button[4], "3, 3, c, c"); // Center
     frame.add (button[5], "3, 3, 3, 5"); // Overlap
 
     // Allow user to close the window to terminate the program
     frame.addWindowListener
         (new WindowListener()
             {
                 public void windowClosing (WindowEvent e)
                 {
                     System.exit (0);
                 }
 
                 public void windowOpened (WindowEvent e) {}
                 public void windowClosed (WindowEvent e) {}
                 public void windowIconified (WindowEvent e) {}
                 public void windowDeiconified (WindowEvent e) {}
                 public void windowActivated (WindowEvent e) {}
                 public void windowDeactivated (WindowEvent e) {}
             }
         );
 
     // Show frame
     frame.show();
 }
 

Version:

3.2 5/9/04

Author:

Daniel E. Barbalace

See Also:

Serialized Form

Nested Class Summary

static class

TableLayout.Entry

Field Summary

protected static int	C Indicates a column
protected static boolean	checkForComponentOrientationSupport Used to minimize reflection calls
protected int[][]	crOffset Offsets of crs in pixels.
protected int[][]	crSize Sizes of crs in pixels
protected double[][]	crSpec Sizes of crs expressed in absolute and relative terms
protected static double[][]	defaultSize Default row/column size
protected boolean	dirty Indicates whether or not the size of the cells are known for the last known size of the container.
protected int	hGap Horizontal gap between columns
protected LinkedList	list List of components and their sizes
protected static Method	methodGetComponentOrientation Method used to get component orientation while preserving compatability with earlier versions of java.awt.Container.
protected int	oldHeight Previous known height of the container
protected int	oldWidth Previous known width of the container
protected static int	R Indicates a row
protected int	vGap Vertical gap between rows

Fields inherited from interface info.clearthought.layout.TableLayoutConstants

BOTTOM, CENTER, FILL, FULL, LEADING, LEFT, MINIMUM, PREFERRED, RIGHT, TOP, TRAILING

Constructor Summary

TableLayout()
Constructs an instance of TableLayout.

TableLayout(double[][] size)
Constructs an instance of TableLayout.

TableLayout(double[] col, double[] row)
Constructs an instance of TableLayout.

Method Summary

void	addLayoutComponent(Component component, Object constraint) Adds the specified component with the specified name to the layout.
void	addLayoutComponent(String name, Component component) Adds the specified component with the specified name to the layout.
protected int	assignAbsoluteSize(int z, int availableSize) Assigns absolute sizes.
protected void	assignFillSize(int z, int availableSize) Assigns FILL sizes.
protected int	assignPrefMinSize(int z, int availableSize, double typeOfSize) Assigned widths to preferred and minimum size columns and rows.
protected int	assignRelativeSize(int z, int availableSize) Assigns relative sizes.
protected Dimension	calculateLayoutSize(Container container, double typeOfSize) Calculates the preferred or minimum size for the methods preferredLayoutSize and minimumLayoutSize.
protected int	calculateLayoutSize(Container container, int z, double typeOfSize, TableLayout.Entry[] entryList, Dimension[] prefMinSize) Calculates the preferred or minimum size for the method calculateLayoutSize(Container container, double typeOfSize).
protected void	calculateOffset(int z, Insets inset) Calculates the offset of each cr.
protected void	calculateSize(Container container) Calculates the sizes of the rows and columns based on the absolute and relative sizes specified in crSpec[R] and crSpec[C] and the size of the container.
protected int[]	calculateSizeAndOffset(TableLayout.Entry entry, int preferredSize, boolean isColumn) Calculates the vertical/horizontal offset and size of a component.
void	deleteColumn(int i) Deletes a column in this layout.
protected void	deleteCr(int z, int i) Deletes a cr for the methods deleteRow or deleteColumn.
void	deleteRow(int i) Deletes a row in this layout.
double[]	getColumn() Gets the sizes of columns in this layout.
double	getColumn(int i) Gets the width of a single column in this layout.
protected ComponentOrientation	getComponentOrientation(Container container) Gets the container's component orientation.
TableLayoutConstraints	getConstraints(Component component) Gets the constraints of a given component.
int	getHGap() Gets the horizontal gap between colunns.
List	getInvalidEntry() Determines whether or not there are any components with invalid constraints.
float	getLayoutAlignmentX(Container parent) Returns the alignment along the x axis.
float	getLayoutAlignmentY(Container parent) Returns the alignment along the y axis.
int	getNumColumn() Gets the number of columns in this layout.
int	getNumRow() Gets the number of rows in this layout.
List	getOverlappingEntry() Gets a list of overlapping components and their constraints.
double[]	getRow() Gets the height of a single row in this layout.
double	getRow(int i) Gets the sizes of a row in this layout.
int	getVGap() Gets the vertical gap between rows.
protected void	init(double[] col, double[] row) Initializes the TableLayout for all constructors.
void	insertColumn(int i, double size) Inserts a column in this layout.
void	insertCr(int z, int i, double size) Inserts a cr for the methods insertRow or insertColumn.
void	insertRow(int i, double size) Inserts a row in this layout.
void	invalidateLayout(Container target) Invalidates the layout, indicating that if the layout manager has cached information it should be discarded.
void	layoutContainer(Container container) To lay out the specified container using this layout.
Dimension	maximumLayoutSize(Container target) Returns the maximum dimensions for this layout given the components in the specified target container.
Dimension	minimumLayoutSize(Container container) Determines the minimum size of the container argument using this layout.
Dimension	preferredLayoutSize(Container container) Determines the preferred size of the container argument using this layout.
void	removeLayoutComponent(Component component) Removes the specified component from the layout.
void	setColumn(double[] column) Adjusts the number and sizes of rows in this layout.
void	setColumn(int i, double size) Adjusts the width of a single column in this layout.
void	setConstraints(Component component, TableLayoutConstraints constraint) Sets the constraints of a given component.
protected void	setCr(int z, double[] size) Sets the sizes of rows or columns for the methods setRow or setColumn.
protected void	setCr(int z, int i, double size) Sets the sizes of rows or columns for the methods setRow or setColumn.
void	setHGap(int hGap) Sets the horizontal gap between colunns.
void	setRow(double[] row) Adjusts the number and sizes of rows in this layout.
void	setRow(int i, double size) Adjusts the height of a single row in this layout.
void	setVGap(int vGap) Sets the vertical gap between rows.
String	toString() Converts this TableLayout to a string.

Methods inherited from class java.lang.Object

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

Field Detail

defaultSize

protected static final double[][] defaultSize

Default row/column size

C

protected static final int C

Indicates a column

See Also:

Constant Field Values

R

protected static final int R

Indicates a row

See Also:

Constant Field Values

checkForComponentOrientationSupport

protected static boolean checkForComponentOrientationSupport

Used to minimize reflection calls

methodGetComponentOrientation

protected static Method methodGetComponentOrientation

Method used to get component orientation while preserving compatability with earlier versions of java.awt.Container. Necessary for supporting older JDKs and MicroEdition versions of Java.

crSpec

protected double[][] crSpec

Sizes of crs expressed in absolute and relative terms

crSize

protected int[][] crSize

Sizes of crs in pixels

crOffset

protected int[][] crOffset

Offsets of crs in pixels. The left boarder of column n is at crOffset[C][n] and the right boarder is at cr[C][n + 1] for all columns including the last one. crOffset[C].length = crSize[C].length + 1

list

protected LinkedList list

List of components and their sizes

dirty

protected boolean dirty

Indicates whether or not the size of the cells are known for the last known size of the container. If dirty is true or the container has been resized, the cell sizes must be recalculated using calculateSize.

oldWidth

protected int oldWidth

Previous known width of the container

oldHeight

protected int oldHeight

Previous known height of the container

hGap

protected int hGap

Horizontal gap between columns

vGap

protected int vGap

Vertical gap between rows

Constructor Detail

TableLayout

public TableLayout()

Constructs an instance of TableLayout. This TableLayout will have no columns or rows. This constructor is most useful for bean-oriented programming and dynamically adding columns and rows.

TableLayout

public TableLayout(double[][] size)

Constructs an instance of TableLayout.

Parameters:

size - widths of columns and heights of rows in the format, {{col0, col1, col2, ..., colN}, {row0, row1, row2, ..., rowM}} If this parameter is invalid, the TableLayout will have exactly one row and one column.

TableLayout

public TableLayout(double[] col,
                   double[] row)

Constructs an instance of TableLayout.

Parameters:

col - widths of columns in the format, {{col0, col1, col2, ..., colN}

row - heights of rows in the format, {{row0, row1, row2, ..., rowN}

Method Detail

init

protected void init(double[] col,
                    double[] row)

Initializes the TableLayout for all constructors.

Parameters:

col - widths of columns in the format, {{col0, col1, col2, ..., colN}

row - heights of rows in the format, {{row0, row1, row2, ..., rowN}

getConstraints

public TableLayoutConstraints getConstraints(Component component)

Gets the constraints of a given component.

Parameters:

component - desired component

Returns:

If the given component is found, the constraints associated with that component. If the given component is null or is not found, null is returned.

setConstraints

public void setConstraints(Component component,
                           TableLayoutConstraints constraint)

Sets the constraints of a given component.

Parameters:

component - desired component. This parameter cannot be null.

constraint - new set of constraints. This parameter cannot be null.

Returns:

If the given component is found, the constraints associated with that component. If the given component is null or is not found, null is returned.

setColumn

public void setColumn(double[] column)

Adjusts the number and sizes of rows in this layout. After calling this method, the caller should request this layout manager to perform the layout. This can be done with the following code:

     layout.layoutContainer(container);
     container.repaint();
 

or

     window.pack()
 

If this is not done, the changes in the layout will not be seen until the container is resized.

Parameters:

column - widths of each of the columns

See Also:

getColumn()

setRow

public void setRow(double[] row)

Adjusts the number and sizes of rows in this layout. After calling this method, the caller should request this layout manager to perform the layout. This can be done with the following code: layout.layoutContainer(container); container.repaint(); or

     window.pack()
 

If this is not done, the changes in the layout will not be seen until the container is resized.

Parameters:

row - heights of each of the rows. This parameter cannot be null.

See Also:

getRow()

setCr

protected void setCr(int z,
                     double[] size)

Sets the sizes of rows or columns for the methods setRow or setColumn.

Parameters:

z - indicates row or column

size - new cr size

setColumn

public void setColumn(int i,
                      double size)

Adjusts the width of a single column in this layout. After calling this method, the caller should request this layout manager to perform the layout. This can be done with the following code: layout.layoutContainer(container); container.repaint(); or

     window.pack()
 

If this is not done, the changes in the layout will not be seen until the container is resized.

Parameters:

i - zero-based index of column to set. If this parameter is not valid, an ArrayOutOfBoundsException will be thrown.

size - width of the column. This parameter cannot be null.

See Also:

getColumn()

setRow

public void setRow(int i,
                   double size)

Adjusts the height of a single row in this layout. After calling this method, the caller should request this layout manager to perform the layout. This can be done with the following code: layout.layoutContainer(container); container.repaint(); or

     window.pack()
 

If this is not done, the changes in the layout will not be seen until the container is resized.

Parameters:

i - zero-based index of row to set. If this parameter is not valid, an ArrayOutOfBoundsException will be thrown.

size - height of the row. This parameter cannot be null.

See Also:

getRow()

setCr

protected void setCr(int z,
                     int i,
                     double size)

Sets the sizes of rows or columns for the methods setRow or setColumn.

Parameters:

z - indicates row or column

i - indicates which cr to resize

size - new cr size

getColumn

public double[] getColumn()

Gets the sizes of columns in this layout.

Returns:

widths of each of the columns

See Also:

setColumn(double[])

getRow

public double[] getRow()

Gets the height of a single row in this layout.

Returns:

height of the requested row

See Also:

setRow(double[])

getColumn

public double getColumn(int i)

Gets the width of a single column in this layout.

Parameters:

i - zero-based index of row to get. If this parameter is not valid, an ArrayOutOfBoundsException will be thrown.

Returns:

width of the requested column

See Also:

setRow(double[])

getRow

public double getRow(int i)

Gets the sizes of a row in this layout.

Parameters:

i - zero-based index of row to get. If this parameter is not valid, an ArrayOutOfBoundsException will be thrown.

Returns:

height of each of the requested row

See Also:

setRow(double[])

getNumColumn

public int getNumColumn()

Gets the number of columns in this layout.

Returns:

the number of columns

getNumRow

public int getNumRow()

Gets the number of rows in this layout.

Returns:

the number of rows

getHGap

public int getHGap()

Gets the horizontal gap between colunns.

Returns:

the horizontal gap in pixels

getVGap

public int getVGap()

Gets the vertical gap between rows.

Returns:

the vertical gap in pixels

setHGap

public void setHGap(int hGap)

Sets the horizontal gap between colunns.

Parameters:

hGap - the horizontal gap in pixels

setVGap

public void setVGap(int vGap)

Sets the vertical gap between rows.

Parameters:

vGap - the horizontal gap in pixels

insertColumn

public void insertColumn(int i,
                         double size)

Inserts a column in this layout. All components to the right of the insertion point are moved right one column. The container will need to be laid out after this method returns. See setColumn.

Parameters:

i - zero-based index at which to insert the column

size - size of the column to be inserted

See Also:

setColumn(double[]), deleteColumn(int)

insertRow

public void insertRow(int i,
                      double size)

Inserts a row in this layout. All components below the insertion point are moved down one row. The container will need to be laid out after this method returns. See setRow.

Parameters:

i - zero-based index at which to insert the row

size - size of the row to be inserted

See Also:

setRow(double[]), deleteRow(int)

insertCr

public void insertCr(int z,
                     int i,
                     double size)

Inserts a cr for the methods insertRow or insertColumn.

Parameters:

z - indicates row or column

i - zero-based index at which to insert the cr

size - size of cr being inserted

deleteColumn

public void deleteColumn(int i)

Deletes a column in this layout. All components to the right of the deletion point are moved left one column. The container will need to be laid out after this method returns. See setColumn.

Parameters:

i - zero-based index of column to delete

See Also:

setColumn(double[]), deleteColumn(int)

deleteRow

public void deleteRow(int i)

Deletes a row in this layout. All components below the deletion point are moved up one row. The container will need to be laid out after this method returns. See setRow. There must be at least two rows in order to delete a row.

Parameters:

i - zero-based index of row to delete

See Also:

setRow(double[]), deleteRow(int)

deleteCr

protected void deleteCr(int z,
                        int i)

Deletes a cr for the methods deleteRow or deleteColumn.

Parameters:

z - indicates row or column

i - zero-based index of cr to delete

toString

public String toString()

Converts this TableLayout to a string.

Returns:

a string representing the columns and row sizes in the form "{{col0, col1, col2, ..., colN}, {row0, row1, row2, ..., rowM}}"

getInvalidEntry

public List getInvalidEntry()

Determines whether or not there are any components with invalid constraints. An invalid constraint is one that references a non-existing row or column. For example, on a table with five rows, row -1 and row 5 are both invalid. Valid rows are 0 through 4, inclusively.

Returns:

a list of TableLayout.Entry instances refering to the invalid constraints and corresponding components

See Also:

getOverlappingEntry()

getOverlappingEntry

public List getOverlappingEntry()

Gets a list of overlapping components and their constraints. Two components overlap if they cover at least one common cell.

Returns:

a list of zero or more TableLayout.Entry instances

See Also:

getInvalidEntry()

calculateSize

protected void calculateSize(Container container)

Calculates the sizes of the rows and columns based on the absolute and relative sizes specified in crSpec[R] and crSpec[C] and the size of the container. The result is stored in crSize[R] and crSize[C].

Parameters:

container - container using this TableLayout

assignAbsoluteSize

protected int assignAbsoluteSize(int z,
                                 int availableSize)

Assigns absolute sizes.

Parameters:

z - indicates row or column

availableSize - amount of space available in the container

Returns:

the amount of space available after absolute crs have been assigned sizes

assignRelativeSize

protected int assignRelativeSize(int z,
                                 int availableSize)

Assigns relative sizes.

Parameters:

z - indicates row or column

availableSize - amount of space available in the container

Returns:

the amount of space available after relative crs have been assigned sizes

assignFillSize

protected void assignFillSize(int z,
                              int availableSize)

Assigns FILL sizes.

Parameters:

z - indicates row or column

availableSize - amount of space available in the container

Returns:

the amount of space available after fill crs have been assigned sizes

calculateOffset

protected void calculateOffset(int z,
                               Insets inset)

Calculates the offset of each cr.

Parameters:

z - indicates row or column

assignPrefMinSize

protected int assignPrefMinSize(int z,
                                int availableSize,
                                double typeOfSize)

Assigned widths to preferred and minimum size columns and rows. This reduces the available width and height. Minimum widths/heights must be calculated first because they affect preferred widths/heights, but not vice versa. The end result is that any component contained wholly or partly in a column/row of minimum/preferred width will get at least its minimum/preferred width, respectively.

Parameters:

z - indicates row or column

availableSize - amount of space available in the container

typeOfSize - indicates preferred or minimum

Returns:

the amount of space available after absolute crs have been assigned sizes

layoutContainer

public void layoutContainer(Container container)

To lay out the specified container using this layout. This method reshapes the components in the specified target container in order to satisfy the constraints of all components.

User code should not have to call this method directly.

Specified by:

layoutContainer in interface LayoutManager

Parameters:

container - container being served by this layout manager

getComponentOrientation

protected ComponentOrientation getComponentOrientation(Container container)

Gets the container's component orientation. If a JDK that does not support component orientation is being used, then null is returned.

Parameters:

container - Container whose orientation is being queried

Returns:

the container's orientation or null if no orientation is supported

calculateSizeAndOffset

protected int[] calculateSizeAndOffset(TableLayout.Entry entry,
                                       int preferredSize,
                                       boolean isColumn)

Calculates the vertical/horizontal offset and size of a component.

Parameters:

entry - entry containing component and contraints

preferredSize - previously calculated preferred width/height of component

isColumn - if true, this method is being called to calculate the offset/size of a column. if false,... of a row.

Returns:

an array, a, of two integers such that a[0] is the offset and a[1] is the size

preferredLayoutSize

public Dimension preferredLayoutSize(Container container)

Determines the preferred size of the container argument using this layout. The preferred size is the smallest size that, if used for the container's size, will ensure that all components are at least as large as their preferred size. This method cannot guarantee that all components will be their preferred size. For example, if component A and component B are each allocate half of the container's width and component A wants to be 10 pixels wide while component B wants to be 100 pixels wide, they cannot both be accommodated. Since in general components rather be larger than their preferred size instead of smaller, component B's request will be fulfilled. The preferred size of the container would be 200 pixels.

Specified by:

preferredLayoutSize in interface LayoutManager

Parameters:

container - container being served by this layout manager

Returns:

a dimension indicating the container's preferred size

minimumLayoutSize

public Dimension minimumLayoutSize(Container container)

Determines the minimum size of the container argument using this layout. The minimum size is the smallest size that, if used for the container's size, will ensure that all components are at least as large as their minimum size. This method cannot guarantee that all components will be their minimum size. For example, if component A and component B are each allocate half of the container's width and component A wants to be 10 pixels wide while component B wants to be 100 pixels wide, they cannot both be accommodated. Since in general components rather be larger than their minimum size instead of smaller, component B's request will be fulfilled. The minimum size of the container would be 200 pixels.

Specified by:

minimumLayoutSize in interface LayoutManager

Parameters:

container - container being served by this layout manager

Returns:

a dimension indicating the container's minimum size

calculateLayoutSize

protected Dimension calculateLayoutSize(Container container,
                                        double typeOfSize)

Calculates the preferred or minimum size for the methods preferredLayoutSize and minimumLayoutSize.

Parameters:

container - container whose size is being calculated

typeOfSize - indicates preferred or minimum

Returns:

a dimension indicating the container's preferred or minimum size

calculateLayoutSize

protected int calculateLayoutSize(Container container,
                                  int z,
                                  double typeOfSize,
                                  TableLayout.Entry[] entryList,
                                  Dimension[] prefMinSize)

Calculates the preferred or minimum size for the method calculateLayoutSize(Container container, double typeOfSize). This method is passed the preferred/minimum sizes of the components so that the potentially expensive methods getPreferredSize()/getMinimumSize() are not called twice for the same component.

Parameters:

container - container whose size is being calculated

typeOfSize - indicates preferred or minimum

entryList - list of Entry objects

prefMinSize - list of preferred or minimum sizes

Returns:

a dimension indicating the container's preferred or minimum size

addLayoutComponent

public void addLayoutComponent(String name,
                               Component component)

Adds the specified component with the specified name to the layout.

Specified by:

addLayoutComponent in interface LayoutManager

Parameters:

name - indicates entry's position and anchor

component - component to add

addLayoutComponent

public void addLayoutComponent(Component component,
                               Object constraint)

Adds the specified component with the specified name to the layout.

Specified by:

addLayoutComponent in interface LayoutManager2

Parameters:

component - component to add

constraint - indicates entry's position and alignment

removeLayoutComponent

public void removeLayoutComponent(Component component)

Removes the specified component from the layout.

Specified by:

removeLayoutComponent in interface LayoutManager

Parameters:

component - component being removed

maximumLayoutSize

public Dimension maximumLayoutSize(Container target)

Returns the maximum dimensions for this layout given the components in the specified target container.

Specified by:

maximumLayoutSize in interface LayoutManager2

Parameters:

target - the component which needs to be laid out

Returns:

unconditionally, a Dimension of Integer.MAX_VALUE by Integer.MAX_VALUE since TableLayout does not limit the maximum size of a container

getLayoutAlignmentX

public float getLayoutAlignmentX(Container parent)

Returns the alignment along the x axis. This specifies how the component would like to be aligned relative to other components. The value should be a number between 0 and 1 where 0 represents alignment along the origin, 1 is aligned the furthest away from the origin, 0.5 is centered, etc.

Specified by:

getLayoutAlignmentX in interface LayoutManager2

Returns:

unconditionally, 0.5

getLayoutAlignmentY

public float getLayoutAlignmentY(Container parent)

Returns the alignment along the y axis. This specifies how the component would like to be aligned relative to other components. The value should be a number between 0 and 1 where 0 represents alignment along the origin, 1 is aligned the furthest away from the origin, 0.5 is centered, etc.

Specified by:

getLayoutAlignmentY in interface LayoutManager2

Returns:

unconditionally, 0.5

invalidateLayout

public void invalidateLayout(Container target)

Invalidates the layout, indicating that if the layout manager has cached information it should be discarded.

Specified by:

invalidateLayout in interface LayoutManager2