Package org.evoludo.graphics

Class AbstractGraph<B>

Object

UIObject

Widget

Panel

SimplePanel

FocusPanel

AbstractGraph<B>

Type Parameters:

B - the type of buffer backing the graph: typically this is double[] but in some cases Color[], String[] or MeshLambertMaterial[] for Pop2D, PopGraph2D or PopGraph3D, respectively.

All Implemented Interfaces:

HasAllDragAndDropHandlers, HasAllFocusHandlers, HasAllGestureHandlers, HasAllKeyHandlers, HasAllMouseHandlers, HasAllTouchHandlers, HasBlurHandlers, HasClickHandlers, HasContextMenuHandlers, HasDoubleClickHandlers, HasDragEndHandlers, HasDragEnterHandlers, HasDragHandlers, HasDragLeaveHandlers, HasDragOverHandlers, HasDragStartHandlers, HasDropHandlers, HasFocusHandlers, HasGestureChangeHandlers, HasGestureEndHandlers, HasGestureStartHandlers, HasKeyDownHandlers, HasKeyPressHandlers, HasKeyUpHandlers, HasMouseDownHandlers, HasMouseMoveHandlers, HasMouseOutHandlers, HasMouseOverHandlers, HasMouseUpHandlers, HasMouseWheelHandlers, HasTouchCancelHandlers, HasTouchEndHandlers, HasTouchMoveHandlers, HasTouchStartHandlers, MouseDownHandler, MouseMoveHandler, MouseOutHandler, MouseUpHandler, MouseWheelHandler, TouchEndHandler, TouchMoveHandler, TouchStartHandler, HasAttachHandlers, EventHandler, HasHandlers, EventListener, AcceptsOneWidget, Focusable, HasFocus, HasOneWidget, HasVisibility, HasWidgets, HasWidgets.ForIsWidget, IsWidget, RequiresResize, SourcesClickEvents, SourcesFocusEvents, SourcesKeyboardEvents, SourcesMouseEvents, SourcesMouseWheelEvents, Iterable<Widget>, ContextMenu.Listener, ContextMenu.Provider, Tooltip.Provider

Direct Known Subclasses:

GenericPopGraph, HistoGraph, LineGraph, ParaGraph, S3Graph

public abstract class AbstractGraph<B>
extends FocusPanel
implements MouseOutHandler, MouseWheelHandler, MouseDownHandler, MouseUpHandler, MouseMoveHandler, TouchStartHandler, TouchEndHandler, TouchMoveHandler, RequiresResize, Tooltip.Provider, ContextMenu.Listener, ContextMenu.Provider

The base class for all graphical representations. The class provides the basic functionality for drawing graphs, handling mouse and touch events, and displaying tooltips and context menus. It also provides the default implementations for zooming and shifting the view of the graph.

Author:

Christoph Hauert

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	AbstractGraph.Controller	The base interface for communicating with the controller of all graphs.
static class	AbstractGraph.GraphStyle	The style features for graphs.
static interface	AbstractGraph.HasTrajectory	Graphs that show trajectories and support exporting their data should implement this interface.
static class	AbstractGraph.MyContext2d	Create custom Context2d that admits drawing dashed lines.
static interface	AbstractGraph.Shifter	Graphs that support shifting of their view should implement this interface.
static interface	AbstractGraph.Shifting	Graphs that support shifting should implement this interface.
class	AbstractGraph.ZoomCommand	The zoom command for the context menu.
static interface	AbstractGraph.Zoomer	Graphs that support zooming should implement this interface.
static interface	AbstractGraph.Zooming	Graphs that support zooming should implement this interface.

Nested classes/interfaces inherited from class UIObject

UIObject.DebugIdImpl, UIObject.DebugIdImplEnabled

Nested classes/interfaces inherited from interface HasWidgets

HasWidgets.ForIsWidget

Field Summary

Fields

Modifier and Type	Field	Description
protected Rectangle2D	bounds	The bounds of the displaying area.
protected RingBuffer<B>	buffer	The buffer to store historical data, if applicable.
private ContextMenu	bufferSizeMenu	The context menu to set the buffer size for graphs with historical data.
private ContextMenuItem	bufferSizeTrigger	The context menu item which triggers the buffer size context menu.
protected Canvas	canvas	Handle to the canvas for drawing the graphics.
protected String[]	colors	The array of colors used for drawing the graph.
protected ContextMenu	contextMenu	The reference to the (shared) context menu.
protected AbstractGraph.Controller	controller	The controller of this graph.
protected static final int	DEFAULT_BUFFER_SIZE	The default buffer size.
(package private) HandlerRegistration	doubleClickHandler	The handler for DoubleClickEvents.
protected Element	element	Handle to the object's underlying DOM element.
protected AbstractGraph.MyContext2d	g	Handle to the graphical context for drawing on the canvas.
protected boolean	hasMessage	Flag to indicate whether the graph displays a message.
protected boolean	hasZoom	The flag to indicate whether the graph supports zoom.
protected boolean	isActive	The flag to indicate whether the graph is live (visible, activated).
protected boolean	leftMouseButton	The flag to indicate whether the left mouse button is pressed.
protected Logger	logger	Logger for keeping track of and reporting events and issues.
protected String[]	markerColors	The array of colors used for markers.
protected ArrayList<double[]>	markers	Markers for decorating the graph.
private static final int	MAX_SEGEMENTS	The maximum number of line segments to draw before returning control to the event loop.
protected static final int	MIN_BUFFER_SIZE	The minimum buffer size.
static final int	MIN_MSEC_BETWEEN_UPDATES	The minimum time between updates in milliseconds.
protected Module	module	The module backing the graph.
(package private) HandlerRegistration	mouseDownHandler	The handler for MouseDownEvents.
(package private) HandlerRegistration	mouseMoveHandler	The handler for MouseMoveEvents.
(package private) HandlerRegistration	mouseOutHandler	The handler for MouseOutEvents.
(package private) HandlerRegistration	mouseUpHandler	The handler for MouseUpEvents.
(package private) HandlerRegistration	mouseWheelHandler	The handler for MouseWheelEvents.
protected int	mouseX	The x-coordinate of the previous mouse or tap event.
protected int	mouseY	The y-coordinate of the previous mouse or tap event.
protected static final double	PIHALF	Constant representing the numerical value of $\pi /2$
protected double	pinchDist	The distance between the pinching gesture.
protected int	pinchX	The x-coordinate of the center of the pinching gesture.
protected int	pinchY	The y-coordinate of the center of the pinching gesture.
protected double	scale	The scale of this graph.
(package private) AbstractGraph.Shifter	shifter	The controller for shifting this graph.
protected AbstractGraph.GraphStyle	style	The style of the graph.
protected Tooltip	tooltip	The reference to the (shared) tooltip.
(package private) BasicTooltipProvider	tooltipProvider	The provider for tooltips.
(package private) HandlerRegistration	touchEndHandler	The handler for TouchEndEvents.
protected double	touchEndTime	The time when the previous touch ended.
(package private) HandlerRegistration	touchMoveHandler	The handler for TouchMoveEvents.
(package private) HandlerRegistration	touchStartHandler	The handler for TouchStartEvents.
private static final double	TWOPI	Constant representing the numerical value of $2\pi$
protected double	updatetime	The field to store the time of the last update.
protected Point2D	viewCorner	The coordinates of the lower left corner visible on the canvas.
(package private) LayoutPanel	wrapper	The wrapper element which displays the canvas.
(package private) AbstractGraph.Zoomer	zoomer	The controller for zooming this graph.
protected double	zoomFactor	The current zoom level.
protected Timer	zoomInertiaTimer	The timer to remove the CSS classes .evoludo-cursorZoomIn or .evoludo-cursorZoomIn, respectively, from the graph element after the inertia of zooming has worn off.
(package private) ContextMenuItem	zoomInMenu	The context menu item to zoom in (enlarge) by a factor of 2.
(package private) ContextMenuItem	zoomOutMenu	The context menu item to zoom out (reduce) by a factor of 1/2.
(package private) ContextMenuItem	zoomResetMenu	The context menu item to reset the zoom level.

Fields inherited from class UIObject

DEBUG_ID_PREFIX

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractGraph(AbstractGraph.Controller controller, Module module)	Create the base class for graphs.

Method Summary

Modifier and Type	Method	Description
void	activate()	Perform necessary preparations to show the graph in the GUI.
HandlerRegistration	addContextMenuHandler(ContextMenuHandler handler)
void	autoscale(boolean x, boolean y)	Set auto-scaling for horizontal and vertical axes.
protected boolean	calcBounds()	Calculate bounds of drawing area.
void	calcBounds(int width, int height)	Calculate bounds of drawing area.
protected void	clearCanvas()	Clear the canvas.
void	clearGraph()	Clear the graph.
void	clearHistory()	Clear the history of the graph (if there is one).
void	clearMessage()	Clear the message.
private void	closePath(boolean fill)	Helper method to close the path and draw (or fill) it.
boolean	contains(int x, int y)	Checks if the (browser) coordinates (x, y) are inside this graph.
Point2D	convertToScaledCoordinates(int x, int y)	Convert the (browser) coordinates (x, y) to scaled coordinates in $[0,1{]}^2$.
Point2D	convertToScaledCoordinates(int x, int y, Point2D dest)	Convert the (browser) coordinates (x, y) to scaled coordinates in $[0,1{]}^2$ and store in dest.
void	deactivate()	The graph is removed from the GUI.
boolean	displayMessage(String msg)	Display message msg on the graph (no HTML formatting).
boolean	doUpdate()	Determine whether it is time to update the display.
protected void	drawFrame(int xLevels, int yLevels)	Draw the frame of the graph including axis labels, ticks and tick marks, as applicable.
protected void	drawFrame(int xLevels, int yLevels, double gscale)	Draw the frame of the graph including axis labels, ticks and tick marks, as applicable, after scaling the canvas by gscale.
abstract void	export(AbstractGraph.MyContext2d ctx)	Export the graphical context ctx.
protected void	fill(Path2D path)	Fill the path path.
protected void	fillCircle(double x, double y, double radius)	Fill the circle with the center at (x,y) and radius radius.
protected void	fillRect(double x, double y, double w, double h)	Fill the rectangle with origin at (x,y), width w and height h.
protected void	fillTextVertical(String msg, double x, double y)	Draw filled text vertically starting at point (x,y)
RingBuffer<B>	getBuffer()	Return the RingBuffer<double[]> containing historical data, if applicable.
Module	getModule()	Get the module that backs the graph.
AbstractGraph.GraphStyle	getStyle()	Get the graph style.
boolean	hasHistory()	Check whether the graph entertains a buffer with historical data.
boolean	hasMessage()	Check if the graph displays a message.
void	init()	Initialize the graph.
void	onMouseDown(MouseDownEvent event)
void	onMouseMove(MouseMoveEvent event)
void	onMouseOut(MouseOutEvent event)
void	onMouseUp(MouseUpEvent event)
void	onMouseWheel(MouseWheelEvent event)
void	onResize()
void	onTouchEnd(TouchEndEvent event)
void	onTouchMove(TouchMoveEvent event)
void	onTouchStart(TouchStartEvent event)
void	paint()	Draw the graph.
boolean	paint(boolean force)	Draw the graph.
void	populateContextMenuAt(ContextMenu menu, int x, int y)	Populate context menu menu in listening widget at (relative) position (x,y).
protected double[]	prependTime2Data(double t, double[] data)	Utility method to prepend time to data point.
void	reset()	Reset the graph.
protected void	resetTransforms()	Reset the transformation of the graphics context to the identity transform.
protected void	setBufferCapacity(int capacity)	Sets the buffer capacity to capacity, if applicable.
void	setColors(String[] colors)	Assign a list of colors to the graph.
protected void	setFont(String cssfont)	Set the font to cssfont in CSS format for drawing on the canvas.
void	setMarkers(ArrayList<double[]> markers)	Assign a list of markers to the graph.
void	setMarkers(ArrayList<double[]> markers, String[] colors)	Assign a list of markers with custom colors to the graph.
protected void	setStrokeStyleAt(int node)	Set the stroke colour for node with index node.
void	setTooltipProvider(BasicTooltipProvider tooltipProvider)	Set the provider for tooltips.
void	shift(int dx, int dy)	Shift the (zoomed) graph within the view port by (dx, dy).
private void	sketch(Path2D path, boolean fill)	Draw or fill (if fill == true) the path path.
private void	sketchCircle(double x, double y, double radius)	Helper method to create a path for a circle with the center at (x,y) and radius radius.
protected void	stroke(Path2D path)	Draw the path path.
protected void	strokeCircle(double x, double y, double radius)	Draw the circle with the center at (x,y) and radius radius.
protected void	strokeLine(double sx, double sy, double ex, double ey)	Draw a line from point (sx,sy) to (ex,ey).
protected void	strokeRect(double x, double y, double w, double h)	Draw the rectangle with origin at (x,y), width w and height h.
private void	updateCanvas()	Update the canvas size and coordinate space dimensions.
void	zoom()	Reset zoom.
void	zoom(double zoom)	Adjust zoom level by the factor zoom.
protected void	zoom(double zoom, double fx, double fy)	Helper method to adjust zoom level with the zoom center at the scaled coordinates (fx, fy), specified as a fraction of the view port in horizontal and vertical directions, respectively.
void	zoom(double zoom, int x, int y)	Adjust zoom level by the factor zoom with the center at coordinates (x,y) (in display coordinates as provided by event listeners).

Methods inherited from class FocusPanel

addBlurHandler, addClickHandler, addClickListener, addDoubleClickHandler, addDragEndHandler, addDragEnterHandler, addDragHandler, addDragLeaveHandler, addDragOverHandler, addDragStartHandler, addDropHandler, addFocusHandler, addFocusListener, addGestureChangeHandler, addGestureEndHandler, addGestureStartHandler, addKeyboardListener, addKeyDownHandler, addKeyPressHandler, addKeyUpHandler, addMouseDownHandler, addMouseListener, addMouseMoveHandler, addMouseOutHandler, addMouseOverHandler, addMouseUpHandler, addMouseWheelHandler, addMouseWheelListener, addTouchCancelHandler, addTouchEndHandler, addTouchMoveHandler, addTouchStartHandler, getTabIndex, removeClickListener, removeFocusListener, removeKeyboardListener, removeMouseListener, removeMouseWheelListener, setAccessKey, setFocus, setTabIndex

Methods inherited from class SimplePanel

add, getContainerElement, getWidget, iterator, remove, setWidget, setWidget

Methods inherited from class Panel

add, adopt, clear, doAttachChildren, doDetachChildren, orphan, remove

Methods inherited from class Widget

addAttachHandler, addBitlessDomHandler, addDomHandler, addHandler, asWidget, asWidgetOrNull, createHandlerManager, delegateEvent, fireEvent, getHandlerCount, getLayoutData, getParent, isAttached, isOrWasAttached, onAttach, onBrowserEvent, onDetach, onLoad, onUnload, removeFromParent, setLayoutData, sinkEvents, unsinkEvents

Methods inherited from class UIObject

addStyleDependentName, addStyleName, ensureDebugId, ensureDebugId, ensureDebugId, getAbsoluteLeft, getAbsoluteTop, getElement, getOffsetHeight, getOffsetWidth, getStyleElement, getStyleName, getStyleName, getStylePrimaryName, getStylePrimaryName, getTitle, isVisible, isVisible, onEnsureDebugId, removeStyleDependentName, removeStyleName, resolvePotentialElement, setElement, setElement, setHeight, setPixelSize, setSize, setStyleDependentName, setStyleName, setStyleName, setStyleName, setStyleName, setStylePrimaryName, setStylePrimaryName, setTitle, setVisible, setVisible, setWidth, sinkBitlessEvent, toString

Methods inherited from class Object

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

Methods inherited from interface ContextMenu.Listener

getAbsoluteLeft, getAbsoluteTop

Methods inherited from interface HasHandlers

fireEvent

Methods inherited from interface HasTouchCancelHandlers

addTouchCancelHandler

Methods inherited from interface HasTouchEndHandlers

addTouchEndHandler

Methods inherited from interface HasTouchMoveHandlers

addTouchMoveHandler

Methods inherited from interface HasTouchStartHandlers

addTouchStartHandler

Methods inherited from interface Iterable

forEach, spliterator

Methods inherited from interface Tooltip.Provider

getTooltipAt

Field Details

doubleClickHandler

HandlerRegistration doubleClickHandler

The handler for DoubleClickEvents.

mouseOutHandler

HandlerRegistration mouseOutHandler

The handler for MouseOutEvents.

mouseDownHandler

HandlerRegistration mouseDownHandler

The handler for MouseDownEvents.

mouseUpHandler

HandlerRegistration mouseUpHandler

The handler for MouseUpEvents.

mouseMoveHandler

HandlerRegistration mouseMoveHandler

The handler for MouseMoveEvents.

mouseWheelHandler

HandlerRegistration mouseWheelHandler

The handler for MouseWheelEvents.

touchStartHandler

HandlerRegistration touchStartHandler

The handler for TouchStartEvents.

touchEndHandler

HandlerRegistration touchEndHandler

The handler for TouchEndEvents.

touchMoveHandler

HandlerRegistration touchMoveHandler

The handler for TouchMoveEvents.

zoomFactor

protected double zoomFactor

The current zoom level.

viewCorner

protected Point2D viewCorner

The coordinates of the lower left corner visible on the canvas.

controller

protected AbstractGraph.Controller controller

The controller of this graph.

shifter

AbstractGraph.Shifter shifter

The controller for shifting this graph.

zoomer

AbstractGraph.Zoomer zoomer

The controller for zooming this graph.

contextMenu

protected ContextMenu contextMenu

The reference to the (shared) context menu.

tooltip

protected Tooltip tooltip

The reference to the (shared) tooltip.

tooltipProvider

BasicTooltipProvider tooltipProvider

The provider for tooltips.

scale

protected double scale

The scale of this graph. Used to translate width and height into canvas coordinates. For example, on retina displays the scale is typically 2, i.e. two pixels per unit width or height.

See Also:

• NativeJS.getDevicePixelRatio()
• Canvas.setCoordinateSpaceWidth(int)
• Canvas.setCoordinateSpaceHeight(int)

wrapper

LayoutPanel wrapper

The wrapper element which displays the canvas. Subclasses may use this to add further elements to the graph such as labels.

logger

protected Logger logger

Logger for keeping track of and reporting events and issues.

element

protected Element element

Handle to the object's underlying DOM element.

canvas

protected Canvas canvas

Handle to the canvas for drawing the graphics.

g

protected AbstractGraph.MyContext2d g

Handle to the graphical context for drawing on the canvas.

colors

protected String[] colors

The array of colors used for drawing the graph.

markers

protected ArrayList<double[]> markers

Markers for decorating the graph.

markerColors

protected String[] markerColors

The array of colors used for markers.

module

protected Module module

The module backing the graph.

isActive

protected boolean isActive

The flag to indicate whether the graph is live (visible, activated).

bounds

protected Rectangle2D bounds

The bounds of the displaying area. This excludes any frames and/or axis labels.

style

protected AbstractGraph.GraphStyle style

The style of the graph. Includes labels, fonts, etc.

buffer

protected RingBuffer<B> buffer

The buffer to store historical data, if applicable.

MIN_BUFFER_SIZE

protected static final int MIN_BUFFER_SIZE

The minimum buffer size.

See Also:

• Constant Field Values

DEFAULT_BUFFER_SIZE

protected static final int DEFAULT_BUFFER_SIZE

The default buffer size. Must be at least MIN_BUFFER_SIZE.

See Also:

• Constant Field Values

MIN_MSEC_BETWEEN_UPDATES

public static final int MIN_MSEC_BETWEEN_UPDATES

The minimum time between updates in milliseconds.

See Also:

• Constant Field Values

updatetime

protected double updatetime

The field to store the time of the last update.

bufferSizeMenu

private ContextMenu bufferSizeMenu

The context menu to set the buffer size for graphs with historical data.

bufferSizeTrigger

private ContextMenuItem bufferSizeTrigger

The context menu item which triggers the buffer size context menu.

hasZoom

protected boolean hasZoom

The flag to indicate whether the graph supports zoom. The default is no support.

zoomResetMenu

ContextMenuItem zoomResetMenu

The context menu item to reset the zoom level.

zoomInMenu

ContextMenuItem zoomInMenu

The context menu item to zoom in (enlarge) by a factor of 2.

zoomOutMenu

ContextMenuItem zoomOutMenu

The context menu item to zoom out (reduce) by a factor of 1/2.

TWOPI

private static final double TWOPI

Constant representing the numerical value of $2\pi$

See Also:

• Constant Field Values

PIHALF

protected static final double PIHALF

Constant representing the numerical value of $\pi /2$

See Also:

• Constant Field Values

MAX_SEGEMENTS

private static final int MAX_SEGEMENTS

The maximum number of line segments to draw before returning control to the event loop.

See Also:

• Constant Field Values

hasMessage

protected boolean hasMessage

Flag to indicate whether the graph displays a message.

leftMouseButton

protected boolean leftMouseButton

The flag to indicate whether the left mouse button is pressed.

mouseX

protected int mouseX

The x-coordinate of the previous mouse or tap event.

mouseY

protected int mouseY

The y-coordinate of the previous mouse or tap event.

touchEndTime

protected double touchEndTime

The time when the previous touch ended.

pinchX

protected int pinchX

The x-coordinate of the center of the pinching gesture.

pinchY

protected int pinchY

The y-coordinate of the center of the pinching gesture.

pinchDist

protected double pinchDist

The distance between the pinching gesture.

zoomInertiaTimer

protected Timer zoomInertiaTimer

The timer to remove the CSS classes .evoludo-cursorZoomIn or .evoludo-cursorZoomIn, respectively, from the graph element after the inertia of zooming has worn off.

Constructor Details

AbstractGraph

protected AbstractGraph(AbstractGraph.Controller controller,
 Module module)

Create the base class for graphs. Allocates the canvas, retrieves the shared tooltip and context menu. Use the CSS class evoludo-Canvas2D for custom formatting of the canvas element.

Parameters:

controller - the controller of this graph

module - the module backing the graph

Method Details

setTooltipProvider

public void setTooltipProvider(BasicTooltipProvider tooltipProvider)

Set the provider for tooltips.

Parameters:

tooltipProvider - the provider for tooltips

getBuffer

public RingBuffer<B> getBuffer()

Return the RingBuffer<double[]> containing historical data, if applicable.

Returns:

the buffer with historical data or null

doUpdate

public boolean doUpdate()

Determine whether it is time to update the display.

Returns:

true if time to update graph

activate

public void activate()

Perform necessary preparations to show the graph in the GUI. Attaches mouse and touch handlers for graphs that implement AbstractGraph.Zooming or AbstractGraph.Shifting interfaces.

See Also:

• deactivate()

deactivate

public void deactivate()

The graph is removed from the GUI. Opportunity for some clean up. Removes all mouse and touch handlers from graph.

See Also:

• activate()

onResize

public void onResize()

Specified by:

onResize in interface RequiresResize

updateCanvas

private void updateCanvas()

Update the canvas size and coordinate space dimensions. IMPORTANT: Setting the canvas size or the coordinate space dimensions clears the canvas (even with no actual changes)!

reset

public void reset()

Reset the graph. Clear canvas and messages.

init

public void init()

Initialize the graph. Do not clear graph.

paint

public void paint()

Draw the graph.

getModule

public Module getModule()

Get the module that backs the graph.

Returns:

the module

paint

public boolean paint(boolean force)

Draw the graph. For re-drawing the graph, set force to true.

Parameters:

force - true to force re-drawing of graph

Returns:

true if painting skipped

setMarkers

public void setMarkers(ArrayList<double[]> markers)

Assign a list of markers to the graph.

Parameters:

markers - the list of markers

setMarkers

public void setMarkers(ArrayList<double[]> markers,
 String[] colors)

Assign a list of markers with custom colors to the graph.

Parameters:

markers - the list of markers

colors - the list of custom colors

setColors

public void setColors(String[] colors)

Assign a list of colors to the graph.

Parameters:

colors - the list of colors

hasHistory

public boolean hasHistory()

Check whether the graph entertains a buffer with historical data.

Returns:

true if the graph stores the data history

clearHistory

public void clearHistory()

Clear the history of the graph (if there is one).

prependTime2Data

protected double[] prependTime2Data(double t,
 double[] data)

Utility method to prepend time to data point.

Parameters:

t - the time

data - the data

Returns:

the new data array including time

populateContextMenuAt

public void populateContextMenuAt(ContextMenu menu,
 int x,
 int y)

Populate context menu menu in listening widget at (relative) position (x,y).

Adds buffer size menu and queries the controller to add further functionality.

Specified by:

populateContextMenuAt in interface ContextMenu.Provider

Parameters:

menu - context menu entries are added here

x - horizontal coordinate (relative to listening widget)

y - horizontal coordinate (relative to listening widget)

See Also:

• AbstractGraph.Controller.populateContextMenu(ContextMenu)

setBufferCapacity

protected void setBufferCapacity(int capacity)

Sets the buffer capacity to capacity, if applicable.

Parameters:

capacity - the new buffer capacity

contains

public boolean contains(int x,
 int y)

Checks if the (browser) coordinates (x, y) are inside this graph. This is useful for controllers that may manage several graphs.

Parameters:

x - the x-coordinate to check

y - the y-coordinate to check

Returns:

true if (x, y) is inside graph

convertToScaledCoordinates

public Point2D convertToScaledCoordinates(int x,
 int y)

Convert the (browser) coordinates (x, y) to scaled coordinates in $[0,1{]}^2$.

Parameters:

x - the x-coordinate to convert

y - the y-coordinate to convert

Returns:

the converted coordinates

convertToScaledCoordinates

public Point2D convertToScaledCoordinates(int x,
 int y,
 Point2D dest)

Convert the (browser) coordinates (x, y) to scaled coordinates in $[0,1{]}^2$ and store in dest.

Parameters:

x - the x-coordinate to convert

y - the y-coordinate to convert

dest - the point to save the converted coordinates

Returns:

the converted coordinates

export

public abstract void export(AbstractGraph.MyContext2d ctx)

Export the graphical context ctx.

Parameters:

ctx - the graphical context to export

calcBounds

protected boolean calcBounds()

Calculate bounds of drawing area. If element has never been visible its size is not yet known.

Returns:

true if bounds are successfully calculated.

calcBounds

public void calcBounds(int width,
 int height)

Calculate bounds of drawing area.

Parameters:

width - the width of the drawing area

height - the height of the drawing area

drawFrame

protected void drawFrame(int xLevels,
 int yLevels)

Draw the frame of the graph including axis labels, ticks and tick marks, as applicable.

Implementation Note:

The top, left corner of the canvas is assumed to be at (0, 0). Flips the direction of the y-axis.

Parameters:

xLevels - the number of vertical levels

yLevels - the number of horizontal levels

See Also:

• AbstractGraph.GraphStyle

drawFrame

protected void drawFrame(int xLevels,
 int yLevels,
 double gscale)

Draw the frame of the graph including axis labels, ticks and tick marks, as applicable, after scaling the canvas by gscale.

Implementation Note:

After scaling the origin (0, 0) is assumed to be in the bottom, left corner of the canvas.

Parameters:

xLevels - the number of vertical levels

yLevels - the number of horizontal levels

gscale - the scaling applied to the coordinate transformation

setFont

protected void setFont(String cssfont)

Set the font to cssfont in CSS format for drawing on the canvas.

Parameters:

cssfont - the font for drawing

setStrokeStyleAt

protected void setStrokeStyleAt(int node)

Set the stroke colour for node with index node.

Parameters:

node - the index of the node

stroke

protected void stroke(Path2D path)

Draw the path path.

Parameters:

path - the path to draw

fill

protected void fill(Path2D path)

Fill the path path.

Parameters:

path - the path to fill

sketch

private void sketch(Path2D path,
 boolean fill)

Draw or fill (if fill == true) the path path.

Implementation notes:

• Drawing too many segments at once becomes very slow (why?).
• Periodically closing and stroking the path is orders of magnitudes faster!
• This simple change renders freezing of the GUI essentially a non issue.
• SVG seems to be a stickler about opening and closing paths or empty paths (see Canvas2SVG.js)

Parameters:

path - the path to draw (or fill)

fill - true to fill path

closePath

private void closePath(boolean fill)

Helper method to close the path and draw (or fill) it.

Parameters:

fill - true to fill path

strokeRect

protected void strokeRect(double x,
 double y,
 double w,
 double h)

Draw the rectangle with origin at (x,y), width w and height h.

Parameters:

x - the x-coordinate of the origin

y - the y-coordinate of the origin

w - the width of the rectangle

h - the height of the rectangle

fillRect

protected void fillRect(double x,
 double y,
 double w,
 double h)

Fill the rectangle with origin at (x,y), width w and height h.

Parameters:

x - the x-coordinate of the origin

y - the y-coordinate of the origin

w - the width of the rectangle

h - the height of the rectangle

strokeCircle

protected void strokeCircle(double x,
 double y,
 double radius)

Draw the circle with the center at (x,y) and radius radius.

Parameters:

x - the x-coordinate of the center

y - the y-coordinate of the center

radius - the radius of the circle

fillCircle

protected void fillCircle(double x,
 double y,
 double radius)

Fill the circle with the center at (x,y) and radius radius.

Parameters:

x - the x-coordinate of the center

y - the y-coordinate of the center

radius - the radius of the circle

sketchCircle

private void sketchCircle(double x,
 double y,
 double radius)

Helper method to create a path for a circle with the center at (x,y) and radius radius.

Parameters:

x - the x-coordinate of the center

y - the y-coordinate of the center

radius - the radius of the circle

strokeLine

protected void strokeLine(double sx,
 double sy,
 double ex,
 double ey)

Draw a line from point (sx,sy) to (ex,ey).

Parameters:

sx - the x-coordinate of the start point

sy - the y-coordinate of the start point

ex - the x-coordinate of the end point

ey - the y-coordinate of the end point

fillTextVertical

protected void fillTextVertical(String msg,
 double x,
 double y)

Draw filled text vertically starting at point (x,y)

Parameters:

msg - the text to write

x - the x-coordinate of the start point

y - the y-coordinate of the start point

clearGraph

public void clearGraph()

Clear the graph.

clearCanvas

protected void clearCanvas()

Clear the canvas.

Implementation note:

Assumes scaled canvas coordinates, i.e. lower, left corner at (0,0).

resetTransforms

protected void resetTransforms()

Reset the transformation of the graphics context to the identity transform.

displayMessage

public boolean displayMessage(String msg)

Display message msg on the graph (no HTML formatting).

Implementation note:

The message is centered and scaled such that it fills approximately two thirds of the width of the graph.

Parameters:

msg - the message to display

Returns:

true if message displayed

clearMessage

public void clearMessage()

Clear the message.

hasMessage

public boolean hasMessage()

Check if the graph displays a message.

Returns:

true if message displayed

zoom

public void zoom()

Reset zoom. Default implementation for graphs that implement Zooming.

See Also:

• AbstractGraph.Zooming.zoom()

zoom

public void zoom(double zoom)

Adjust zoom level by the factor zoom. Default implementation for graphs that implement Zooming.

Parameters:

zoom - the new zoom level

See Also:

• AbstractGraph.Zooming.zoom(double)

zoom

public void zoom(double zoom,
 int x,
 int y)

Adjust zoom level by the factor zoom with the center at coordinates (x,y) (in display coordinates as provided by event listeners). Default implementation for graphs that implement Zooming.

Parameters:

zoom - the new zoom level

x - the x-coordinate of the zoom center

y - the y-coordinate of the zoom center

See Also:

• AbstractGraph.Zoomer.zoom(double, int, int)

zoom

protected void zoom(double zoom,
 double fx,
 double fy)

Helper method to adjust zoom level with the zoom center at the scaled coordinates (fx, fy), specified as a fraction of the view port in horizontal and vertical directions, respectively.

Parameters:

zoom - the new zoom level

fx - the scaled x-coordinate of the zoom center

fy - the scaled y-coordinate of the zoom center

See Also:

• onMouseWheel(MouseWheelEvent)
• onTouchMove(TouchMoveEvent)

shift

public void shift(int dx,
 int dy)

Shift the (zoomed) graph within the view port by (dx, dy). Default implementation for graphs that implement Shifting.

Parameters:

dx - the horizontal shift of the graph

dy - the vertical shift of the graph

See Also:

• AbstractGraph.Shifter.shift(int, int)

onMouseOut

public void onMouseOut(MouseOutEvent event)

If mouse leaves graph while shifting the view stop shifting. Mouse events are no longer received and hence it is impossible to track releasing or pressing mouse buttons.

Specified by:

onMouseOut in interface MouseOutHandler

onMouseDown

public void onMouseDown(MouseDownEvent event)

If a node has been hit by a left-click, remember the node's index and the current mouse coordinates. This information might be used by subsequent MouseMoveEvents.

Specified by:

onMouseDown in interface MouseDownHandler

See Also:

• onMouseMove(MouseMoveEvent)

onMouseUp

public void onMouseUp(MouseUpEvent event)

Cancel all interactions with the graph and reset node and mouse information.

CSS Style Rules

.evoludo-cursorMoveView

removed from graph element.

Specified by:

onMouseUp in interface MouseUpHandler

See Also:

• onMouseMove(MouseMoveEvent)

onMouseMove

public void onMouseMove(MouseMoveEvent event)

If the left mouse-key is pressed the graph is shifted within its viewport. Note this requires that the zoom level of the graph exceeds 1.

CSS Style Rules

.evoludo-cursorMoveView

added to graph element when shifting the view.

Specified by:

onMouseMove in interface MouseMoveHandler

See Also:

• onMouseDown(MouseDownEvent)

onMouseWheel

public void onMouseWheel(MouseWheelEvent event)

Adjusts the zoom level of the graph, while preserving the location of the mouse on the graph. The zooming has inertia.

CSS Style Rules

.evoludo-cursorZoomIn

added to graph element when zooming in and removed when inertia stops.

.evoludo-cursorZoomOut

added to graph element when zooming out and removed when inertia stops.

Specified by:

onMouseWheel in interface MouseWheelHandler

See Also:

• zoom(double, int, int)
• zoomInertiaTimer

onTouchStart

public void onTouchStart(TouchStartEvent event)

The graph reacts to different kinds of touches: short touches or taps (<250 msec) and long touches (>250 msec). Long touches trigger different actions depending on the number of fingers:

Single finger

Initiate shifting the view

Two fingers

Initiate pinching zoom.

Specified by:

onTouchStart in interface TouchStartHandler

See Also:

• onTouchMove(TouchMoveEvent)

onTouchEnd

public void onTouchEnd(TouchEndEvent event)

The number of touches on the graph changed.

Specified by:

onTouchEnd in interface TouchEndHandler

onTouchMove

public void onTouchMove(TouchMoveEvent event)

The graph reacts to different kinds of touch moves:

Move one finger

Shift view

Pinch two fingers

Zoom view

Specified by:

onTouchMove in interface TouchMoveHandler

addContextMenuHandler

public HandlerRegistration addContextMenuHandler(ContextMenuHandler handler)

Specified by:

addContextMenuHandler in interface HasContextMenuHandlers

getStyle

public AbstractGraph.GraphStyle getStyle()

Get the graph style.

Returns:

the graph style

autoscale

public void autoscale(boolean x,
 boolean y)

Set auto-scaling for horizontal and vertical axes.

Parameters:

x - true to automatically scale the x-axis

y - true to automatically scale the y-axis