QwtPlotCanvas(3)

💖 QwtPlotCanvas(3) 💖

okay bestie, welcome to the QwtPlotCanvas page from the Qwt User's Guide — yes it's a section 3 manual page, and yes it's lowkey iconic. grab a boba, we're doing this 🧋✨

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🌸 NAME 🌸

QwtPlotCanvas — that's it, that's the name. it's a class, she's mysterious, she's the canvas of a QwtPlot.

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✨ SYNOPSIS ✨

#include <qwt_plot_canvas.h>

🎀 Public Types

enum FocusIndicator { NoFocusIndicator, CanvasFocusIndicator,
    ItemFocusIndicator }
enum PaintAttribute { PaintCached =  1, PaintPacked =  2 }

🦋 Public Member Functions

QwtPlotCanvas (QwtPlot *)
virtual ~QwtPlotCanvas ()
FocusIndicator focusIndicator () const
void invalidatePaintCache ()
QPixmap * paintCache ()
const QPixmap * paintCache () const
QwtPlot * plot ()
const QwtPlot * plot () const
void replot ()
void setFocusIndicator (FocusIndicator)
void setPaintAttribute (PaintAttribute, bool on=true)
bool testPaintAttribute (PaintAttribute) const

🌈 Protected Member Functions

void drawCanvas (QPainter *painter=NULL)
virtual void drawContents (QPainter *)
virtual void drawFocusIndicator (QPainter *)
virtual void hideEvent (QHideEvent *)
virtual void paintEvent (QPaintEvent *)

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👑 Detailed Description 👑

Canvas of a QwtPlot. she IS the moment, fr fr. 💅

See also:

• QwtPlot

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💜 Member Enumeration Documentation 💜

enum QwtPlotCanvas::FocusIndicator

Focus indicator. the way this enum has exactly three moods:

• NoFocusIndicator — don't paint a focus indicator. simply not participating. 🙈
• CanvasFocusIndicator — the focus is related to the complete canvas. paint the focus indicator using paintFocus()
• ItemFocusIndicator — the focus is related to an item (curve, point, ...) on the canvas. it is up to the application to display a focus indication using f.e. highlighting.

See also:

• setFocusIndicator(), focusIndicator(), paintFocus()

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enum QwtPlotCanvas::PaintAttribute

Paint attributes. two of them, both bangers:

• PaintCached — paint double buffered and reuse the content of the pixmap buffer for some spontaneous repaints that happen when a plot gets unhidden, deiconified or changes the focus. disabling the cache will improve the performance for incremental paints (using QwtPlotCurve::draw). no cap, turning the cache off genuinely helps incremental paints. ⚡
• PaintPacked — suppress system background repaints and paint it together with the canvas contents. painting packed might avoid flickering for expensive repaints, when there is a notable gap between painting the background and the plot contents.

The default setting enables PaintCached and PaintPacked. 🫶

See also:

• setPaintAttribute(), testPaintAttribute(), paintCache()

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🌟 Member Function Documentation 🌟

void QwtPlotCanvas::drawCanvas (QPainter *painter = NULL) [protected]

Draw the the canvas. (yes, "the the", we're keeping it exactly as written, she's got a lil typo and we love her anyway 😭)

Paints all plot items to the contentsRect(), using QwtPlot::drawCanvas and updates the paint cache. she does the work AND updates the receipts. multitasking queen.

Parameters:

• painter — Painter

See also:

• QwtPlot::drawCanvas(), setPaintAttributes(), testPaintAttributes()

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void QwtPlotCanvas::drawContents (QPainter *painter) [protected], [virtual]

Redraw the canvas, and focus rect.

Parameters:

• painter — Painter

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void QwtPlotCanvas::drawFocusIndicator (QPainter *painter) [protected], [virtual]

Draw the focus indication.

Parameters:

• painter — Painter

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QwtPlotCanvas::FocusIndicator QwtPlotCanvas::focusIndicator () const

Returns:

• Focus indicator

See also:

• FocusIndicator, setFocusIndicator()

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void QwtPlotCanvas::hideEvent (QHideEvent *event) [protected], [virtual]

Hide event.

Parameters:

• event — Hide event

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

Paint event.

Parameters:

• event — Paint event

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void QwtPlotCanvas::replot ()

Invalidate the paint cache and repaint the canvas. out with the old pixels, in with the new. ✨

See also:

• invalidatePaintCache()

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void QwtPlotCanvas::setFocusIndicator (FocusIndicatorfocusIndicator)

Set the focus indicator.

See also:

• FocusIndicator, focusIndicator()

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void QwtPlotCanvas::setPaintAttribute (PaintAttributeattribute, boolon = true)

Changing the paint attributes.

Parameters:

• attribute — Paint attribute
• on — On/Off

The default setting enables PaintCached and PaintPacked.

See also:

• testPaintAttribute(), drawCanvas(), drawContents(), paintCache()

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bool QwtPlotCanvas::testPaintAttribute (PaintAttributeattribute) const

Test wether a paint attribute is enabled. (again, "wether", leaving it exactly as-is, periodt 💀)

Parameters:

• attribute — Paint attribute

Returns:

• true if the attribute is enabled

See also:

• setPaintAttribute()

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🎀 Author 🎀

Generated automatically by Doxygen for Qwt User's Guide from the source code. so technically the author is a robot and honestly? she ate. 🤖💖

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aaand that's the whole page bestie, you made it to the end, so proud of you 🥹✨

this was Version 5.2.3, dated Tue Nov 20 2012 — a vintage queen serving looks since 2012. mwah, go forth and paint your canvas. 💅🦋🌸