.TH "QwtPlotZoomer" 3 "Mon Dec 28 2020" "Version 6.1.6" "Qwt User's Guide" \" -*- nroff -*-
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.SH NAME
QwtPlotZoomer \- \fBQwtPlotZoomer\fP provides stacked zooming for a plot widget\&.  

.SH SYNOPSIS
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.PP
.PP
\fC#include <qwt_plot_zoomer\&.h>\fP
.PP
Inherits \fBQwtPlotPicker\fP\&.
.SS "Public Slots"

.in +1c
.ti -1c
.RI "void \fBmoveBy\fP (double dx, double dy)"
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.ti -1c
.RI "virtual void \fBmoveTo\fP (const QPointF &)"
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.ti -1c
.RI "virtual void \fBzoom\fP (const QRectF &)"
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.RI "Zoom in\&. "
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.RI "virtual void \fBzoom\fP (int offset)"
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.RI "Zoom in or out\&. "
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.SS "Signals"

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.RI "void \fBzoomed\fP (const QRectF &rect)"
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.SS "Public Member Functions"

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.RI "\fBQwtPlotZoomer\fP (QWidget *, bool doReplot=true)"
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.RI "Create a zoomer for a plot canvas\&. "
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.RI "\fBQwtPlotZoomer\fP (int \fBxAxis\fP, int \fByAxis\fP, QWidget *, bool doReplot=true)"
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.RI "Create a zoomer for a plot canvas\&. "
.ti -1c
.RI "virtual void \fBsetZoomBase\fP (bool doReplot=true)"
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.RI "virtual void \fBsetZoomBase\fP (const QRectF &)"
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.RI "Set the initial size of the zoomer\&. "
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.RI "QRectF \fBzoomBase\fP () const"
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.RI "QRectF \fBzoomRect\fP () const"
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.RI "virtual void \fBsetAxis\fP (int \fBxAxis\fP, int \fByAxis\fP)"
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.RI "void \fBsetMaxStackDepth\fP (int)"
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.RI "Limit the number of recursive zoom operations to depth\&. "
.ti -1c
.RI "int \fBmaxStackDepth\fP () const"
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.ti -1c
.RI "const QStack< QRectF > & \fBzoomStack\fP () const"
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.ti -1c
.RI "void \fBsetZoomStack\fP (const QStack< QRectF > &, int \fBzoomRectIndex\fP=\-1)"
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.RI "Assign a zoom stack\&. "
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.RI "uint \fBzoomRectIndex\fP () const"
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.SS "Protected Member Functions"

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.RI "virtual void \fBrescale\fP ()"
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.RI "virtual QSizeF \fBminZoomSize\fP () const"
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.RI "Limit zooming by a minimum rectangle\&. "
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.RI "virtual void \fBwidgetMouseReleaseEvent\fP (QMouseEvent *)"
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.RI "virtual void \fBwidgetKeyPressEvent\fP (QKeyEvent *)"
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.RI "virtual void \fBbegin\fP ()"
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.RI "virtual bool \fBend\fP (bool ok=true)"
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.RI "virtual bool \fBaccept\fP (QPolygon &) const"
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.RI "Check and correct a selected rectangle\&. "
.in -1c
.SS "Additional Inherited Members"
.SH "Detailed Description"
.PP 
\fBQwtPlotZoomer\fP provides stacked zooming for a plot widget\&. 

\fBQwtPlotZoomer\fP selects rectangles from user inputs ( mouse or keyboard ) translates them into plot coordinates and adjusts the axes to them\&. The selection is supported by a rubber band and optionally by displaying the coordinates of the current mouse position\&.
.PP
Zooming can be repeated as often as possible, limited only by \fBmaxStackDepth()\fP or \fBminZoomSize()\fP\&. Each rectangle is pushed on a stack\&.
.PP
The default setting how to select rectangles is a \fBQwtPickerDragRectMachine\fP with the following bindings:
.PP
.IP "\(bu" 2
\fBQwtEventPattern::MouseSelect1\fP
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 The first point of the zoom rectangle is selected by a mouse press, the second point from the position, where the mouse is released\&.
.IP "\(bu" 2
\fBQwtEventPattern::KeySelect1\fP
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 The first key press selects the first, the second key press selects the second point\&.
.IP "\(bu" 2
\fBQwtEventPattern::KeyAbort\fP
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 Discard the selection in the state, where the first point is selected\&.
.PP
.PP
To traverse the zoom stack the following bindings are used:
.PP
.IP "\(bu" 2
\fBQwtEventPattern::MouseSelect3\fP, \fBQwtEventPattern::KeyUndo\fP
.br
 Zoom out one position on the zoom stack
.IP "\(bu" 2
\fBQwtEventPattern::MouseSelect6\fP, \fBQwtEventPattern::KeyRedo\fP
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 Zoom in one position on the zoom stack
.IP "\(bu" 2
\fBQwtEventPattern::MouseSelect2\fP, \fBQwtEventPattern::KeyHome\fP
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 Zoom to the zoom base
.PP
.PP
The \fBsetKeyPattern()\fP and \fBsetMousePattern()\fP functions can be used to configure the zoomer actions\&. The following example shows, how to configure the 'I' and 'O' keys for zooming in and out one position on the zoom stack\&. The 'Home' key is used to 'unzoom' the plot\&.
.PP
.PP
.nf
zoomer = new QwtPlotZoomer( plot );
zoomer->setKeyPattern( QwtEventPattern::KeyRedo, Qt::Key_I, Qt::ShiftModifier );
zoomer->setKeyPattern( QwtEventPattern::KeyUndo, Qt::Key_O, Qt::ShiftModifier );
zoomer->setKeyPattern( QwtEventPattern::KeyHome, Qt::Key_Home );
.fi
.PP
.PP
\fBQwtPlotZoomer\fP is tailored for plots with one x and y axis, but it is allowed to attach a second \fBQwtPlotZoomer\fP ( without rubber band and tracker ) for the other axes\&.
.PP
\fBNote\fP
.RS 4
The realtime example includes an derived zoomer class that adds scrollbars to the plot canvas\&.
.RE
.PP
\fBSee also\fP
.RS 4
\fBQwtPlotPanner\fP, \fBQwtPlotMagnifier\fP 
.RE
.PP

.SH "Constructor & Destructor Documentation"
.PP 
.SS "QwtPlotZoomer::QwtPlotZoomer (QWidget * canvas, bool doReplot = \fCtrue\fP)\fC [explicit]\fP"

.PP
Create a zoomer for a plot canvas\&. The zoomer is set to those x- and y-axis of the parent plot of the canvas that are enabled\&. If both or no x-axis are enabled, the picker is set to \fBQwtPlot::xBottom\fP\&. If both or no y-axis are enabled, it is set to \fBQwtPlot::yLeft\fP\&.
.PP
The zoomer is initialized with a \fBQwtPickerDragRectMachine\fP, the tracker mode is set to \fBQwtPicker::ActiveOnly\fP and the rubber band is set to \fBQwtPicker::RectRubberBand\fP
.PP
\fBParameters\fP
.RS 4
\fIcanvas\fP Plot canvas to observe, also the parent object 
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\fIdoReplot\fP Call \fBQwtPlot::replot()\fP for the attached plot before initializing the zoomer with its scales\&. This might be necessary, when the plot is in a state with pending scale changes\&.
.RE
.PP
\fBSee also\fP
.RS 4
\fBQwtPlot::autoReplot()\fP, \fBQwtPlot::replot()\fP, \fBsetZoomBase()\fP 
.RE
.PP

.SS "QwtPlotZoomer::QwtPlotZoomer (int xAxis, int yAxis, QWidget * canvas, bool doReplot = \fCtrue\fP)\fC [explicit]\fP"

.PP
Create a zoomer for a plot canvas\&. The zoomer is initialized with a \fBQwtPickerDragRectMachine\fP, the tracker mode is set to \fBQwtPicker::ActiveOnly\fP and the rubber band is set to \fBQwtPicker\fP;;RectRubberBand
.PP
\fBParameters\fP
.RS 4
\fIxAxis\fP X axis of the zoomer 
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\fIyAxis\fP Y axis of the zoomer 
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\fIcanvas\fP Plot canvas to observe, also the parent object 
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\fIdoReplot\fP Call \fBQwtPlot::replot()\fP for the attached plot before initializing the zoomer with its scales\&. This might be necessary, when the plot is in a state with pending scale changes\&.
.RE
.PP
\fBSee also\fP
.RS 4
\fBQwtPlot::autoReplot()\fP, \fBQwtPlot::replot()\fP, \fBsetZoomBase()\fP 
.RE
.PP

.SH "Member Function Documentation"
.PP 
.SS "bool QwtPlotZoomer::accept (QPolygon & pa) const\fC [protected]\fP, \fC [virtual]\fP"

.PP
Check and correct a selected rectangle\&. Reject rectangles with a height or width < 2, otherwise expand the selected rectangle to a minimum size of 11x11 and accept it\&.
.PP
\fBReturns\fP
.RS 4
true If the rectangle is accepted, or has been changed to an accepted one\&. 
.RE
.PP

.PP
Reimplemented from \fBQwtPicker\fP\&.
.SS "void QwtPlotZoomer::begin ()\fC [protected]\fP, \fC [virtual]\fP"
Rejects selections, when the stack depth is too deep, or the zoomed rectangle is \fBminZoomSize()\fP\&.
.PP
\fBSee also\fP
.RS 4
\fBminZoomSize()\fP, \fBmaxStackDepth()\fP 
.RE
.PP

.PP
Reimplemented from \fBQwtPicker\fP\&.
.SS "bool QwtPlotZoomer::end (bool ok = \fCtrue\fP)\fC [protected]\fP, \fC [virtual]\fP"
Expand the selected rectangle to \fBminZoomSize()\fP and zoom in if accepted\&.
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\fBParameters\fP
.RS 4
\fIok\fP If true, complete the selection and emit selected signals otherwise discard the selection\&.
.RE
.PP
\fBSee also\fP
.RS 4
\fBaccept()\fP, \fBminZoomSize()\fP 
.RE
.PP
\fBReturns\fP
.RS 4
True if the selection has been accepted, false otherwise 
.RE
.PP

.PP
Reimplemented from \fBQwtPlotPicker\fP\&.
.SS "int QwtPlotZoomer::maxStackDepth () const"

.PP
\fBReturns\fP
.RS 4
Maximal depth of the zoom stack\&. 
.RE
.PP
\fBSee also\fP
.RS 4
\fBsetMaxStackDepth()\fP 
.RE
.PP

.SS "QSizeF QwtPlotZoomer::minZoomSize () const\fC [protected]\fP, \fC [virtual]\fP"

.PP
Limit zooming by a minimum rectangle\&. 
.PP
\fBReturns\fP
.RS 4
\fBzoomBase()\fP\&.width() / 10e4, \fBzoomBase()\fP\&.height() / 10e4 
.RE
.PP

.SS "void QwtPlotZoomer::moveBy (double dx, double dy)\fC [slot]\fP"
Move the current zoom rectangle\&.
.PP
\fBParameters\fP
.RS 4
\fIdx\fP X offset 
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\fIdy\fP Y offset
.RE
.PP
\fBNote\fP
.RS 4
The changed rectangle is limited by the zoom base 
.RE
.PP

.SS "void QwtPlotZoomer::moveTo (const QPointF & pos)\fC [virtual]\fP, \fC [slot]\fP"
Move the the current zoom rectangle\&.
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\fBParameters\fP
.RS 4
\fIpos\fP New position
.RE
.PP
\fBSee also\fP
.RS 4
QRectF::moveTo() 
.RE
.PP
\fBNote\fP
.RS 4
The changed rectangle is limited by the zoom base 
.RE
.PP

.SS "void QwtPlotZoomer::rescale ()\fC [protected]\fP, \fC [virtual]\fP"
Adjust the observed plot to \fBzoomRect()\fP
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\fBNote\fP
.RS 4
Initiates \fBQwtPlot::replot()\fP 
.RE
.PP

.SS "void QwtPlotZoomer::setAxis (int xAxis, int yAxis)\fC [virtual]\fP"
Reinitialize the axes, and set the zoom base to their scales\&.
.PP
\fBParameters\fP
.RS 4
\fIxAxis\fP X axis 
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\fIyAxis\fP Y axis 
.RE
.PP

.PP
Reimplemented from \fBQwtPlotPicker\fP\&.
.SS "void QwtPlotZoomer::setMaxStackDepth (int depth)"

.PP
Limit the number of recursive zoom operations to depth\&. A value of -1 set the depth to unlimited, 0 disables zooming\&. If the current zoom rectangle is below depth, the plot is unzoomed\&.
.PP
\fBParameters\fP
.RS 4
\fIdepth\fP Maximum for the stack depth 
.RE
.PP
\fBSee also\fP
.RS 4
\fBmaxStackDepth()\fP 
.RE
.PP
\fBNote\fP
.RS 4
depth doesn't include the zoom base, so \fBzoomStack()\fP\&.count() might be \fBmaxStackDepth()\fP + 1\&. 
.RE
.PP

.SS "void QwtPlotZoomer::setZoomBase (bool doReplot = \fCtrue\fP)\fC [virtual]\fP"
Reinitialized the zoom stack with \fBscaleRect()\fP as base\&.
.PP
\fBParameters\fP
.RS 4
\fIdoReplot\fP Call \fBQwtPlot::replot()\fP for the attached plot before initializing the zoomer with its scales\&. This might be necessary, when the plot is in a state with pending scale changes\&.
.RE
.PP
\fBSee also\fP
.RS 4
\fBzoomBase()\fP, \fBscaleRect()\fP \fBQwtPlot::autoReplot()\fP, \fBQwtPlot::replot()\fP\&. 
.RE
.PP

.SS "void QwtPlotZoomer::setZoomBase (const QRectF & base)\fC [virtual]\fP"

.PP
Set the initial size of the zoomer\&. base is united with the current \fBscaleRect()\fP and the zoom stack is reinitialized with it as zoom base\&. plot is zoomed to \fBscaleRect()\fP\&.
.PP
\fBParameters\fP
.RS 4
\fIbase\fP Zoom base
.RE
.PP
\fBSee also\fP
.RS 4
\fBzoomBase()\fP, \fBscaleRect()\fP 
.RE
.PP

.SS "void QwtPlotZoomer::setZoomStack (const QStack< QRectF > & zoomStack, int zoomRectIndex = \fC\-1\fP)"

.PP
Assign a zoom stack\&. In combination with other types of navigation it might be useful to modify to manipulate the complete zoom stack\&.
.PP
\fBParameters\fP
.RS 4
\fIzoomStack\fP New zoom stack 
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\fIzoomRectIndex\fP Index of the current position of zoom stack\&. In case of -1 the current position is at the top of the stack\&.
.RE
.PP
\fBNote\fP
.RS 4
The zoomed signal might be emitted\&. 
.RE
.PP
\fBSee also\fP
.RS 4
\fBzoomStack()\fP, \fBzoomRectIndex()\fP 
.RE
.PP

.SS "void QwtPlotZoomer::widgetKeyPressEvent (QKeyEvent * ke)\fC [protected]\fP, \fC [virtual]\fP"
Qt::Key_Plus zooms in, Qt::Key_Minus zooms out one position on the zoom stack, Qt::Key_Escape zooms out to the zoom base\&.
.PP
Changes the current position on the stack, but doesn't pop any rectangle\&.
.PP
\fBNote\fP
.RS 4
The keys codes can be changed, using \fBQwtEventPattern::setKeyPattern\fP: 3, 4, 5 
.RE
.PP

.PP
Reimplemented from \fBQwtPicker\fP\&.
.SS "void QwtPlotZoomer::widgetMouseReleaseEvent (QMouseEvent * me)\fC [protected]\fP, \fC [virtual]\fP"
Qt::MidButton zooms out one position on the zoom stack, Qt::RightButton to the zoom base\&.
.PP
Changes the current position on the stack, but doesn't pop any rectangle\&.
.PP
\fBNote\fP
.RS 4
The mouse events can be changed, using \fBQwtEventPattern::setMousePattern\fP: 2, 1 
.RE
.PP

.PP
Reimplemented from \fBQwtPicker\fP\&.
.SS "void QwtPlotZoomer::zoom (const QRectF & rect)\fC [virtual]\fP, \fC [slot]\fP"

.PP
Zoom in\&. Clears all rectangles above the current position of the zoom stack and pushes the normalized rectangle on it\&.
.PP
\fBNote\fP
.RS 4
If the maximal stack depth is reached, zoom is ignored\&. 
.PP
The zoomed signal is emitted\&. 
.RE
.PP

.SS "void QwtPlotZoomer::zoom (int offset)\fC [virtual]\fP, \fC [slot]\fP"

.PP
Zoom in or out\&. Activate a rectangle on the zoom stack with an offset relative to the current position\&. Negative values of offset will zoom out, positive zoom in\&. A value of 0 zooms out to the zoom base\&.
.PP
\fBParameters\fP
.RS 4
\fIoffset\fP Offset relative to the current position of the zoom stack\&. 
.RE
.PP
\fBNote\fP
.RS 4
The zoomed signal is emitted\&. 
.RE
.PP
\fBSee also\fP
.RS 4
\fBzoomRectIndex()\fP 
.RE
.PP

.SS "QRectF QwtPlotZoomer::zoomBase () const"

.PP
\fBReturns\fP
.RS 4
Initial rectangle of the zoomer 
.RE
.PP
\fBSee also\fP
.RS 4
\fBsetZoomBase()\fP, \fBzoomRect()\fP 
.RE
.PP

.SS "void QwtPlotZoomer::zoomed (const QRectF & rect)\fC [signal]\fP"
A signal emitting the \fBzoomRect()\fP, when the plot has been zoomed in or out\&.
.PP
\fBParameters\fP
.RS 4
\fIrect\fP Current zoom rectangle\&. 
.RE
.PP

.SS "QRectF QwtPlotZoomer::zoomRect () const"

.PP
\fBReturns\fP
.RS 4
Rectangle at the current position on the zoom stack\&. 
.RE
.PP
\fBSee also\fP
.RS 4
\fBzoomRectIndex()\fP, \fBscaleRect()\fP\&. 
.RE
.PP

.SS "uint QwtPlotZoomer::zoomRectIndex () const"

.PP
\fBReturns\fP
.RS 4
Index of current position of zoom stack\&. 
.RE
.PP

.SS "const QStack< QRectF > & QwtPlotZoomer::zoomStack () const"

.PP
\fBReturns\fP
.RS 4
The zoom stack\&. \fBzoomStack()\fP[0] is the zoom base, \fBzoomStack()\fP[1] the first zoomed rectangle\&.
.RE
.PP
\fBSee also\fP
.RS 4
\fBsetZoomStack()\fP, \fBzoomRectIndex()\fP 
.RE
.PP


.SH "Author"
.PP 
Generated automatically by Doxygen for Qwt User's Guide from the source code\&.