Class ViewHugeTableModel
- java.lang.Object
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- uk.ac.starlink.table.gui.ViewHugeTableModel
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- All Implemented Interfaces:
javax.swing.table.TableModel
public class ViewHugeTableModel extends java.lang.Object implements javax.swing.table.TableModel
Swing TableModel implementation which provides a view on a very large table model.The point of this is for displaying tables with very large row counts in a JTable. Since the default height of a JTable row is 16 pixels (see
JTable.getRowHeight()
) a JTable component with more than 2^27 rows (about 134 million) will have a height in pixels which is too large to represent in a 32-bit int. In that case Swing gives up and just doesn't display the thing.This class implements a model of a fixed (large but not too large) size,
VIEWSIZE
rows, which at any one time gives a view of a contiguous sequence of rows from the base table, starting at a mutable value given bygetViewBase()
. It works out the value of viewBase by reference to a scrollbar which is owned by this model, and assumed to control vertical scrolling of the scroll panel displaying the JTable that views it. The viewBase value is updated dynamically according to the current state (position) of the scrollbar. Whenever the viewBase changes, listeners (most importantly the client JTable) are notified.In principle, every time the scrollbar position, or equivalently the set of currently visible rows, changes, the viewBase should change. But since the scrollbar has only pixel resolution, smallish changes can be accommodated without needing to take the somewhat expensive step of changing the viewBase.
The underlying table model can still only have up to 2^31 rows. The general approach used here would work for larger underlying row data, but it would be necessary to define a new long-capable TableModel interface to accommodate such data.
It is not recommended to use this class for underlying table models which are not in fact huge.
Note this class will only help you for displaying a JTable within a scrollpane. If you want to display a giga-row JTable unscrolled on a 100km tall VDU, you're on your own.
- Since:
- 16 Jul 2014
- Author:
- Mark Taylor
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Field Summary
Fields Modifier and Type Field Description static java.lang.String
VIEWBASE_PROPERTY
Name of property giving underlying value of first row of this model.static int
VIEWSIZE
Fixed number of rows displayed by this model.
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Constructor Summary
Constructors Constructor Description ViewHugeTableModel()
Constructs an empty model.ViewHugeTableModel(javax.swing.table.TableModel hugeModel, javax.swing.JScrollBar vbar)
Constructs a configured model.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
addPropertyChangeListener(java.beans.PropertyChangeListener lnr)
Adds a listener that will be notified about ViewBase changes.void
addTableModelListener(javax.swing.event.TableModelListener lnr)
void
configureModel(javax.swing.table.TableModel hugeModel, javax.swing.JScrollBar vbar)
Sets this mode up for use with a given underlying table model and scroll bar.protected void
firePropertyChanged(java.beans.PropertyChangeEvent evt)
Notifies property change listeners of a property change.protected void
fireTableChanged(javax.swing.event.TableModelEvent evt)
Notifies table model listeners of a table model event.java.lang.Class<?>
getColumnClass(int icol)
int
getColumnCount()
java.lang.String
getColumnName(int icol)
int
getHugeRow(int iViewRow)
Returns the row in the underlying huge model corresponding to a given row in this view.int
getRowCount()
java.lang.Object
getValueAt(int irow, int icol)
int
getViewBase()
Returns the offset from which this view views the underlying table model.boolean
isCellEditable(int irow, int icol)
void
removePropertyChangeListener(java.beans.PropertyChangeListener lnr)
Removes a listener added earlier.void
removeTableModelListener(javax.swing.event.TableModelListener lnr)
void
setValueAt(java.lang.Object value, int irow, int icol)
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Field Detail
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VIEWBASE_PROPERTY
public static final java.lang.String VIEWBASE_PROPERTY
Name of property giving underlying value of first row of this model.- See Also:
- Constant Field Values
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VIEWSIZE
public static final int VIEWSIZE
Fixed number of rows displayed by this model.- See Also:
- Constant Field Values
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Constructor Detail
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ViewHugeTableModel
public ViewHugeTableModel()
Constructs an empty model.
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ViewHugeTableModel
public ViewHugeTableModel(javax.swing.table.TableModel hugeModel, javax.swing.JScrollBar vbar)
Constructs a configured model.- Parameters:
hugeModel
- table model with more than VIEWSIZE rowsvbar
- scrollbar used to control vertical scrolling of table view
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Method Detail
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configureModel
public void configureModel(javax.swing.table.TableModel hugeModel, javax.swing.JScrollBar vbar)
Sets this mode up for use with a given underlying table model and scroll bar.- Parameters:
hugeModel
- table model with more than VIEWSIZE rowsvbar
- scrollbar used to control vertical scrolling of table view
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getRowCount
public int getRowCount()
- Specified by:
getRowCount
in interfacejavax.swing.table.TableModel
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getValueAt
public java.lang.Object getValueAt(int irow, int icol)
- Specified by:
getValueAt
in interfacejavax.swing.table.TableModel
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setValueAt
public void setValueAt(java.lang.Object value, int irow, int icol)
- Specified by:
setValueAt
in interfacejavax.swing.table.TableModel
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isCellEditable
public boolean isCellEditable(int irow, int icol)
- Specified by:
isCellEditable
in interfacejavax.swing.table.TableModel
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getColumnCount
public int getColumnCount()
- Specified by:
getColumnCount
in interfacejavax.swing.table.TableModel
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getColumnName
public java.lang.String getColumnName(int icol)
- Specified by:
getColumnName
in interfacejavax.swing.table.TableModel
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getColumnClass
public java.lang.Class<?> getColumnClass(int icol)
- Specified by:
getColumnClass
in interfacejavax.swing.table.TableModel
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addTableModelListener
public void addTableModelListener(javax.swing.event.TableModelListener lnr)
- Specified by:
addTableModelListener
in interfacejavax.swing.table.TableModel
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removeTableModelListener
public void removeTableModelListener(javax.swing.event.TableModelListener lnr)
- Specified by:
removeTableModelListener
in interfacejavax.swing.table.TableModel
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getViewBase
public int getViewBase()
Returns the offset from which this view views the underlying table model. Changes in this value will be notified to registered PropertyChangeListeners.- Returns:
- view base
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addPropertyChangeListener
public void addPropertyChangeListener(java.beans.PropertyChangeListener lnr)
Adds a listener that will be notified about ViewBase changes. These have the property nameVIEWBASE_PROPERTY
.- Parameters:
lnr
- listener to add
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removePropertyChangeListener
public void removePropertyChangeListener(java.beans.PropertyChangeListener lnr)
Removes a listener added earlier.- Parameters:
lnr
- listener to remove
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fireTableChanged
protected void fireTableChanged(javax.swing.event.TableModelEvent evt)
Notifies table model listeners of a table model event.- Parameters:
evt
- event
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firePropertyChanged
protected void firePropertyChanged(java.beans.PropertyChangeEvent evt)
Notifies property change listeners of a property change.- Parameters:
evt
- event
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getHugeRow
public int getHugeRow(int iViewRow)
Returns the row in the underlying huge model corresponding to a given row in this view.- Returns:
iViewRow + viewBase
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