PlotWidget Class Reference

Renders a plot and stores it as an image until the next render. More...

#include <DataAnalysis/Plot2D/Widgets/plotwidget.h>

Inherits QFrame.

Signals
void	message (const QString &message)
void	resized (QSize s)
void	titleChanged (const QString &title)

Public Member Functions
	PlotWidget (QWidget *parent=nullptr)
void	render (const Plot &plot, const QSize &plotSize)

Protected Member Functions
void	contextMenuEvent (QContextMenuEvent *event) override
bool	event (QEvent *event) override
void	paintEvent (QPaintEvent *event) override
void	resizeEvent (QResizeEvent *event) override

Detailed Description

Think of this as a caching plotter. Once a Plot has been rendered, it is saved as an image. If the widget is resized, the image is also resized. The resultant image will be distorted, but at least it should be a sufficiently suitable image to show until the plot can be re-rendered. This makes repaints very quick when the widget size is not changed, but more importantly the Plot object only needs to be available for the short period when the image is being updated. The Plot doesn't even have to exist any more after that because only the cached image is used after render() returns. This is the main reason why the widget works as it does, since it allows the widget to be connected to a Plot input/output on a workspace and only require interactions with the workspace itself when the plot changes or the widget is resized. Ordinary repaints don't involve the underlying workspace at all.

Constructor & Destructor Documentation

PlotWidget()

PlotWidget

(

QWidget *

parent = nullptr

)

Member Function Documentation

contextMenuEvent()

void contextMenuEvent ( QContextMenuEvent *  event )

overrideprotected

event()

bool event ( QEvent *  event )

overrideprotected

Silently absorbs tooltip events. All other events are passed through to the base class for normal event handling.

message

void message ( const QString &  message )

signal

paintEvent()

void paintEvent ( QPaintEvent *  event )

overrideprotected

Shows the last rendered image, scaled to fit if necessary.

render()

void render	(	const Plot &	plot,
		const QSize &	plotSize
	)

Parameters

plot

The plot whose data should be rendered.

plotSize

The desired size to render to. Note that because calls to render() can be made from any thread, not just the widget's thread, it cannot be assumed that the widget's size is what should be used. Update the cached image used during repaints. The current size of the widget determines the size of the image. Once render() returns, no further reference is made to plot. In fact, plot can safely be deleted immediately after render() returns.

resized

void resized ( QSize  s )

signal

resizeEvent()

void resizeEvent ( QResizeEvent *  event )

overrideprotected

Normally, a resize event triggers an immediate repaint. That's fine, but we also emit a resized() event to allow an external entity to update the image to be painted because the image is now a different size. This means we get a lower quality image immediately and then an improved image after whatever responds to resized() causes the image to be updated via a call to render().

titleChanged

void titleChanged ( const QString &  title )

signal