QwtPlotGLCanvas(3)

📦
version 6.3.0 · 4 versions
, in alpine 3.24

💅 QwtPlotGLCanvas(3) — like, the GL canvas one, bestie

okay so this page lives in the Library Functions Manual, and it's all about QwtPlotGLCanvas — an alternative canvas for a QwtPlot derived from QGLWidget. yes, GL. hardware accelerated. we love to see it ✨

✨ NAME ✨

QwtPlotGLCanvas — an alternative canvas for a QwtPlot derived from QGLWidget. that's the whole vibe, she's a canvas, she's GL-flavored 🎀

🌸 SYNOPSIS 🌸

#include <qwt_plot_glcanvas.h>

Inherits QGLWidget, and QwtPlotAbstractGLCanvas. so she's got family. two families actually 💖

🌈 Public Slots

  • void replot () — makes her redraw, we'll get to that

🦋 Public Member Functions

  • QwtPlotGLCanvas (QwtPlot *=NULL) — Constructor.
  • QwtPlotGLCanvas (const QGLFormat &, QwtPlot *=NULL) — Constructor (the one where you pick your GL format, fancy).
  • virtual ~QwtPlotGLCanvas () — Destructor.
  • virtual Q_INVOKABLE void invalidateBackingStore () override — Invalidate the internal backing store.
  • Q_INVOKABLE QPainterPath borderPath (const QRect &) const — gives you the border path, more below
  • virtual bool event (QEvent *) override — the Qt event handler

💜 Public Member Functions inherited from QwtPlotAbstractGLCanvas

  • QwtPlotAbstractGLCanvas (QWidget *canvasWidget) — Constructor.
  • virtual ~QwtPlotAbstractGLCanvas () — Destructor.
  • void setPaintAttribute (PaintAttribute, bool on=true) — Changing the paint attributes.
  • bool testPaintAttribute (PaintAttribute) const — checks a paint attribute
  • void setFrameStyle (int style) — sets the frame style
  • int frameStyle () const — gets the frame style
  • void setFrameShadow (QFrame::Shadow) — sets the frame shadow
  • QFrame::Shadow frameShadow () const — gets the frame shadow
  • void setFrameShape (QFrame::Shape) — sets the frame shape
  • QFrame::Shape frameShape () const — gets the frame shape
  • void setLineWidth (int) — sets the line width
  • int lineWidth () const — gets the line width
  • void setMidLineWidth (int) — sets the mid line width
  • int midLineWidth () const — gets the mid line width
  • int frameWidth () const — gets the frame width
  • QRect frameRect () const — gets the frame rect

🫶 Public Member Functions inherited from QwtPlotAbstractCanvas

  • QwtPlotAbstractCanvas (QWidget *canvasWidget) — Constructor.
  • virtual ~QwtPlotAbstractCanvas () — Destructor.
  • QwtPlot * plot () — Return parent plot widget.
  • const QwtPlot * plot () const — Return parent plot widget (const edition, she's chill like that).
  • void setFocusIndicator (FocusIndicator) — sets the focus indicator
  • FocusIndicator focusIndicator () const — gets the focus indicator
  • void setBorderRadius (double) — sets the border radius
  • double borderRadius () const — gets the border radius

🧚 Protected Member Functions

  • virtual void paintEvent (QPaintEvent *) override — paints on a paint event
  • virtual void initializeGL () override — No operation - reserved for some potential use in the future.
  • virtual void paintGL () override — Paint the plot.
  • virtual void resizeGL (int width, int height) override — No operation - reserved for some potential use in the future.

💀 Protected Member Functions inherited from QwtPlotAbstractGLCanvas

  • void replot () — the protected replot
  • void draw (QPainter *) — Helper function for the derived plot canvas.

🙈 Protected Member Functions inherited from QwtPlotAbstractCanvas

  • QWidget * canvasWidget () — gives you the canvas widget
  • const QWidget * canvasWidget () const — const version, same deal
  • virtual void drawFocusIndicator (QPainter *) — draws the focus indicator
  • virtual void drawBorder (QPainter *) — draws the border
  • virtual void drawBackground (QPainter *) — Helper function for the derived plot canvas.
  • void fillBackground (QPainter *) — Helper function for the derived plot canvas.
  • void drawCanvas (QPainter *) — Draw the plot to the canvas.
  • void drawStyled (QPainter *, bool) — Helper function for the derived plot canvas.
  • void drawUnstyled (QPainter *) — Helper function for the derived plot canvas.
  • QPainterPath canvasBorderPath (const QRect &rect) const — path for the canvas border
  • void updateStyleSheetInfo () — Update the cached information about the current style sheet.

⭐ Additional Inherited Members

💖 Public Types inherited from QwtPlotAbstractGLCanvas

  • enum PaintAttribute { BackingStore = 1, ImmediatePaint = 8 } — Paint attributes.
  • typedef QFlags< PaintAttribute > PaintAttributes — Paint attributes (the flag-collection era).

🍓 Public Types inherited from QwtPlotAbstractCanvas

  • enum FocusIndicator { NoFocusIndicator, CanvasFocusIndicator, ItemFocusIndicator } — Focus indicator. The default setting is NoFocusIndicator.

👑 Detailed Description 👑

An alternative canvas for a QwtPlot derived from QGLWidget.

QwtPlotGLCanvas implements the very basics to act as canvas inside of a QwtPlot widget. It might be extended to a full featured alternative to QwtPlotCanvas in a future version of Qwt. (so like, she's got potential, she's growing, we're rooting for her 🌱)

Even if QwtPlotGLCanvas is not derived from QFrame it imitates its API. When using style sheets it supports the box model — beside backgrounds with rounded borders. not me being shocked she fakes the whole QFrame thing so convincingly 😭

Since Qt 5.4 QOpenGLWidget is available, that is used by QwtPlotOpenGLCanvas. so if you're on newer Qt, go say hi to her cousin.

See also: QwtPlot::setCanvas(), QwtPlotCanvas, QwtPlotOpenGLCanvas

Note 💀 With Qt4 you might want to use the QPaintEngine::OpenGL paint engine ( see QGL::setPreferredPaintEngine() ). On a Linux test system QPaintEngine::OpenGL2 shows very basic problems like translated geometries. Another way for getting hardware accelerated graphics is using an OpenGL offscreen buffer ( QwtPlotCanvas::OpenGLBuffer ) with QwtPlotCanvas. Performance is worse, than rendering straight to a QGLWidget, but is usually better integrated into a desktop application.

Definition at line 45 of file qwt_plot_glcanvas.h.

🎀 Constructor & Destructor Documentation 🎀

QwtPlotGLCanvas::QwtPlotGLCanvas (QwtPlot * plot = NULL) [explicit]

Constructor.

Parameters

  • plot — Parent plot widget

See also: QwtPlot::setCanvas()

Definition at line 56 of file qwt_plot_glcanvas.cpp.

QwtPlotGLCanvas::QwtPlotGLCanvas (const QGLFormat & format, QwtPlot * plot = NULL) [explicit]

Constructor. this is the one where you hand her a format and she's like "oh we're doing GL options today? slay" 💅

Parameters

  • format — OpenGL rendering options
  • plot — Parent plot widget

See also: QwtPlot::setCanvas()

Definition at line 69 of file qwt_plot_glcanvas.cpp.

QwtPlotGLCanvas::~QwtPlotGLCanvas () [virtual]

Destructor. she's leaving the group chat 😭

Definition at line 77 of file qwt_plot_glcanvas.cpp.

🦋 Member Function Documentation 🦋

QPainterPath QwtPlotGLCanvas::borderPath (const QRect & rect) const

Calculate the painter path for a styled or rounded border.

When the canvas has no styled background or rounded borders the painter path is empty. (empty path, no border, moving on ✨)

Parameters

  • rect — Bounding rectangle of the canvas

Returns

  • Painter path, that can be used for clipping

Definition at line 157 of file qwt_plot_glcanvas.cpp.

void QwtPlotGLCanvas::clearBackingStore () [override], [private], [virtual]

Implements QwtPlotAbstractGLCanvas.

Definition at line 142 of file qwt_plot_glcanvas.cpp.

bool QwtPlotGLCanvas::event (QEvent * event) [override], [virtual]

Qt event handler for QEvent::PolishRequest and QEvent::StyleChange. she's listening, she's paying attention, she knows when you restyle her 🫶

Parameters

  • event — Qt Event

Returns

  • See QGLWidget::event()

Definition at line 110 of file qwt_plot_glcanvas.cpp.

void QwtPlotGLCanvas::initializeGL () [override], [protected], [virtual]

No operation - reserved for some potential use in the future. literally does nothing, and honestly? iconic. she's resting 💀

Definition at line 163 of file qwt_plot_glcanvas.cpp.

void QwtPlotGLCanvas::invalidateBackingStore () [override], [virtual]

Invalidate the internal backing store.

Implements QwtPlotAbstractGLCanvas.

Definition at line 137 of file qwt_plot_glcanvas.cpp.

void QwtPlotGLCanvas::paintEvent (QPaintEvent * event) [override], [protected], [virtual]

Paint event.

Parameters

  • event — Paint event

See also: QwtPlot::drawCanvas()

Definition at line 100 of file qwt_plot_glcanvas.cpp.

void QwtPlotGLCanvas::paintGL () [override], [protected], [virtual]

Paint the plot. that's it, that's the function, she paints the plot 🔥

Definition at line 168 of file qwt_plot_glcanvas.cpp.

void QwtPlotGLCanvas::replot () [slot]

Invalidate the paint cache and repaint the canvas. refresh era 💅

See also: invalidatePaintCache()

Definition at line 131 of file qwt_plot_glcanvas.cpp.

void QwtPlotGLCanvas::resizeGL (int width, int height) [override], [protected], [virtual]

No operation - reserved for some potential use in the future. again! nothing! and we respect it 🧚

Definition at line 233 of file qwt_plot_glcanvas.cpp.

🌈 Author 🌈

Generated automatically by Doxygen for Qwt User's Guide from the source code. so nobody hand-wrote this, the robot did it, and honestly the robot ate 🤖✨

aaand that's the page, bestie 🫶 it came from the Qwt User's Guide (that's the source/version, iykyk) — go build something gorgeous with her, mwah 💖🎀🦋

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