public interface CanvasWidgetHandler

Canvas widget event handler - Java API.

Supports custom drawing functionality - for example can draw molecule mass spectrum, custom charts, etc. Interactivity is enabled by listening on mouse and keyboard events.

Must be implemented as a NetBeans ServiceProvider to be found. Example:

 @ServiceProvider(service = CanvasWidgetHandler.class)
 public class ExampleWidget implements CanvasWidgetHandler {
     @Override
     public void onInit(IJCWidget widget, JPanel canvas, Map config) {
         canvas.setOpaque(true);
         canvas.setBackground(Color.white);
         retrieveData(widget.getForm().getResultSet());
     }

     @Override
     public void onVertexStateChange(IJCWidget widget, JPanel canvas) {
         retrieveData(widget.getForm().getResultSet());
         canvas.repaint();
     }

     @Override
     public void onPaintComponent(IJCWidget widget, JPanel canvas, Graphics g) {
         ... custom drawing of retrieved data ...
     }
 }

Since:: 20.18.0

Method Summary

All Methods Instance Methods Default Methods
Modifier and Type	Method	Description
`default void`	`onDestroy(IJCWidget widget, javax.swing.JPanel canvas, boolean release)`	Called on form suspend or close.
`default void`	`onEDPChange(IJCWidget widget, javax.swing.JPanel canvas)`	Called on entity data provider change - after data update or view reload.
`default void`	`onInit(IJCWidget widget, javax.swing.JPanel canvas, java.util.Map<java.lang.String,java.lang.Object> config)`	Called on form open or resume.
`default void`	`onKeyPressed(IJCWidget widget, javax.swing.JPanel canvas, java.awt.event.KeyEvent event)`	Invoked when a key has been pressed (on a selected canvas component).
`default void`	`onKeyReleased(IJCWidget widget, javax.swing.JPanel canvas, java.awt.event.KeyEvent event)`	Invoked when a key has been released (on a selected canvas component).
`default void`	`onKeyTyped(IJCWidget widget, javax.swing.JPanel canvas, java.awt.event.KeyEvent event)`	Invoked when a key has been typed (on a selected canvas component).
`default void`	`onMouseClicked(IJCWidget widget, javax.swing.JPanel canvas, java.awt.event.MouseEvent event)`	Invoked when the mouse button has been clicked (pressed and released) on a canvas component.
`default void`	`onMouseDragged(IJCWidget widget, javax.swing.JPanel canvas, java.awt.event.MouseEvent event)`	Invoked when a mouse button is pressed on a canvas component and then dragged.
`default void`	`onMouseEntered(IJCWidget widget, javax.swing.JPanel canvas, java.awt.event.MouseEvent event)`	Invoked when the mouse enters a canvas component.
`default void`	`onMouseExited(IJCWidget widget, javax.swing.JPanel canvas, java.awt.event.MouseEvent event)`	Invoked when the mouse exits a canvas component.
`default void`	`onMouseMoved(IJCWidget widget, javax.swing.JPanel canvas, java.awt.event.MouseEvent event)`	Invoked when the mouse cursor has been moved onto a canvas component but no buttons have been pushed.
`default void`	`onMousePressed(IJCWidget widget, javax.swing.JPanel canvas, java.awt.event.MouseEvent event)`	Invoked when a mouse button has been pressed on a canvas component.
`default void`	`onMouseReleased(IJCWidget widget, javax.swing.JPanel canvas, java.awt.event.MouseEvent event)`	Invoked when a mouse button has been released on a canvas component.
`default void`	`onMouseWheelMoved(IJCWidget widget, javax.swing.JPanel canvas, java.awt.event.MouseWheelEvent event)`	Invoked when the mouse wheel is rotated.
`default void`	`onPaintComponent(IJCWidget widget, javax.swing.JPanel canvas, java.awt.Graphics g)`	Called in `paintComponent()` of canvas component.
`default void`	`onPrintRow(IJCWidget widget, java.lang.Comparable<?> rowId)`	Called during printing of a single row.
`default void`	`onVertexStateChange(IJCWidget widget, javax.swing.JPanel canvas)`	Called on vertex state change - after query, selection change, sort change, etc.

Method Detail

onInit
```
default void onInit(IJCWidget widget,
                    javax.swing.JPanel canvas,
                    java.util.Map<java.lang.String,java.lang.Object> config)
```
Called on form open or resume. Also called during Event handler setup in Customizer. Responsible for data retrieval.

Parameters:

widget - IJC widget - has access to current result set and vertex state

canvas - drawing component

config - configuration which was set in a Widget Customizer

onDestroy
```
default void onDestroy(IJCWidget widget,
                       javax.swing.JPanel canvas,
                       boolean release)
```
Called on form suspend or close. Responsible for resources clean-up.

Parameters:

widget - IJC widget

canvas - drawing component

release - false on form suspend, true on form close

onVertexStateChange
```
default void onVertexStateChange(IJCWidget widget,
                                 javax.swing.JPanel canvas)
```
Called on vertex state change - after query, selection change, sort change, etc. Responsible for data retrieval and canvas.repaint().

Parameters:

widget - IJC widget - has access to current result set and vertex state

canvas - drawing component

onEDPChange
```
default void onEDPChange(IJCWidget widget,
                         javax.swing.JPanel canvas)
```
Called on entity data provider change - after data update or view reload. Responsible for data retrieval and canvas.repaint().

Parameters:

widget - IJC widget - has access to current result set and vertex state

canvas - drawing component

onPaintComponent

default void onPaintComponent(IJCWidget widget,
                              javax.swing.JPanel canvas,
                              java.awt.Graphics g)

Called in paintComponent() of canvas component. Responsible for custom drawing.

Parameters:: widget - IJC widget; canvas - drawing component; g - graphics

onPrintRow
```
default void onPrintRow(IJCWidget widget,
                        java.lang.Comparable<?> rowId)
```
Called during printing of a single row. First, this method is called and then onPaintComponent(com.im.ijc.core.api.views.IJCWidget,javax.swing.JPanel,java.awt.Graphics) is called. Responsible for data retrieval.

Parameters:

widget - IJC widget

rowId - printed row id

onMouseClicked
```
default void onMouseClicked(IJCWidget widget,
                            javax.swing.JPanel canvas,
                            java.awt.event.MouseEvent event)
```
Invoked when the mouse button has been clicked (pressed and released) on a canvas component.

Parameters:

widget - IJC widget

canvas - drawing component

event - invoked mouse event

onMousePressed

default void onMousePressed(IJCWidget widget,
                            javax.swing.JPanel canvas,
                            java.awt.event.MouseEvent event)

Invoked when a mouse button has been pressed on a canvas component.

onMouseReleased

default void onMouseReleased(IJCWidget widget,
                             javax.swing.JPanel canvas,
                             java.awt.event.MouseEvent event)

Invoked when a mouse button has been released on a canvas component.

onMouseEntered

default void onMouseEntered(IJCWidget widget,
                            javax.swing.JPanel canvas,
                            java.awt.event.MouseEvent event)

Invoked when the mouse enters a canvas component.

onMouseExited

default void onMouseExited(IJCWidget widget,
                           javax.swing.JPanel canvas,
                           java.awt.event.MouseEvent event)

Invoked when the mouse exits a canvas component.

onMouseDragged

default void onMouseDragged(IJCWidget widget,
                            javax.swing.JPanel canvas,
                            java.awt.event.MouseEvent event)

Invoked when a mouse button is pressed on a canvas component and then dragged.

onMouseMoved

default void onMouseMoved(IJCWidget widget,
                          javax.swing.JPanel canvas,
                          java.awt.event.MouseEvent event)

Invoked when the mouse cursor has been moved onto a canvas component but no buttons have been pushed.

onMouseWheelMoved

default void onMouseWheelMoved(IJCWidget widget,
                               javax.swing.JPanel canvas,
                               java.awt.event.MouseWheelEvent event)

Invoked when the mouse wheel is rotated.

onKeyTyped

default void onKeyTyped(IJCWidget widget,
                        javax.swing.JPanel canvas,
                        java.awt.event.KeyEvent event)

Invoked when a key has been typed (on a selected canvas component).

Parameters:: widget - IJC widget; canvas - drawing component; event - invoked key event

onKeyPressed

default void onKeyPressed(IJCWidget widget,
                          javax.swing.JPanel canvas,
                          java.awt.event.KeyEvent event)

Invoked when a key has been pressed (on a selected canvas component).

onKeyReleased

default void onKeyReleased(IJCWidget widget,
                           javax.swing.JPanel canvas,
                           java.awt.event.KeyEvent event)

Invoked when a key has been released (on a selected canvas component).

Interface CanvasWidgetHandler

Method Summary

Method Detail

onInit

onDestroy

onVertexStateChange

onEDPChange