Qwt User's Guide 5.2.2
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QwtPicker provides selections on a widget. More...
#include <qwt_picker.h>
Public Types | |
enum | DisplayMode { AlwaysOff, AlwaysOn, ActiveOnly } |
enum | KeyPatternCode { KeySelect1, KeySelect2, KeyAbort, KeyLeft, KeyRight, KeyUp, KeyDown, KeyRedo, KeyUndo, KeyHome, KeyPatternCount } |
enum | MousePatternCode { MouseSelect1, MouseSelect2, MouseSelect3, MouseSelect4, MouseSelect5, MouseSelect6, MousePatternCount } |
enum | RectSelectionType { CornerToCorner = 64, CenterToCorner = 128, CenterToRadius = 256 } |
enum | ResizeMode { Stretch, KeepSize } |
enum | RubberBand { NoRubberBand = 0, HLineRubberBand, VLineRubberBand, CrossRubberBand, RectRubberBand, EllipseRubberBand, PolygonRubberBand, UserRubberBand = 100 } |
enum | SelectionMode { ClickSelection = 1024, DragSelection = 2048 } |
enum | SelectionType { NoSelection = 0, PointSelection = 1, RectSelection = 2, PolygonSelection = 4 } |
Signals | |
void | appended (const QPoint &pos) |
void | changed (const QwtPolygon &pa) |
void | moved (const QPoint &pos) |
void | selected (const QwtPolygon &pa) |
Public Member Functions | |
virtual void | drawRubberBand (QPainter *) const |
virtual void | drawTracker (QPainter *) const |
virtual bool | eventFilter (QObject *, QEvent *) |
void | initKeyPattern () |
void | initMousePattern (int numButtons) |
bool | isActive () const |
bool | isEnabled () const |
bool | keyMatch (uint pattern, const QKeyEvent *) const |
const QwtArray< KeyPattern > & | keyPattern () const |
QwtArray< KeyPattern > & | keyPattern () |
bool | mouseMatch (uint pattern, const QMouseEvent *) const |
const QwtArray< MousePattern > & | mousePattern () const |
QwtArray< MousePattern > & | mousePattern () |
QWidget * | parentWidget () |
const QWidget * | parentWidget () const |
virtual QRect | pickRect () const |
QwtPicker (int selectionFlags, RubberBand rubberBand, DisplayMode trackerMode, QWidget *) | |
QwtPicker (QWidget *parent) | |
ResizeMode | resizeMode () const |
RubberBand | rubberBand () const |
QPen | rubberBandPen () const |
const QwtPolygon & | selection () const |
int | selectionFlags () const |
virtual void | setEnabled (bool) |
void | setKeyPattern (uint pattern, int key, int state=Qt::NoButton) |
void | setKeyPattern (const QwtArray< KeyPattern > &) |
void | setMousePattern (uint pattern, int button, int state=Qt::NoButton) |
void | setMousePattern (const QwtArray< MousePattern > &) |
virtual void | setResizeMode (ResizeMode) |
virtual void | setRubberBand (RubberBand) |
virtual void | setRubberBandPen (const QPen &) |
virtual void | setSelectionFlags (int) |
virtual void | setTrackerFont (const QFont &) |
virtual void | setTrackerMode (DisplayMode) |
virtual void | setTrackerPen (const QPen &) |
QFont | trackerFont () const |
DisplayMode | trackerMode () const |
QPen | trackerPen () const |
QPoint | trackerPosition () const |
QRect | trackerRect (const QFont &) const |
virtual QwtText | trackerText (const QPoint &pos) const |
virtual | ~QwtPicker () |
Protected Member Functions | |
virtual bool | accept (QwtPolygon &selection) const |
virtual void | append (const QPoint &) |
virtual void | begin () |
virtual bool | end (bool ok=true) |
virtual bool | keyMatch (const KeyPattern &, const QKeyEvent *) const |
virtual bool | mouseMatch (const MousePattern &, const QMouseEvent *) const |
virtual void | move (const QPoint &) |
virtual void | reset () |
const QWidget * | rubberBandWidget () const |
virtual QwtPickerMachine * | stateMachine (int) const |
virtual void | stretchSelection (const QSize &oldSize, const QSize &newSize) |
const QWidget * | trackerWidget () const |
virtual void | transition (const QEvent *) |
virtual void | updateDisplay () |
virtual void | widgetKeyPressEvent (QKeyEvent *) |
virtual void | widgetKeyReleaseEvent (QKeyEvent *) |
virtual void | widgetLeaveEvent (QEvent *) |
virtual void | widgetMouseDoubleClickEvent (QMouseEvent *) |
virtual void | widgetMouseMoveEvent (QMouseEvent *) |
virtual void | widgetMousePressEvent (QMouseEvent *) |
virtual void | widgetMouseReleaseEvent (QMouseEvent *) |
virtual void | widgetWheelEvent (QWheelEvent *) |
QwtPicker provides selections on a widget.
QwtPicker filters all mouse and keyboard events of a widget and translates them into an array of selected points. Depending on the QwtPicker::SelectionType the selection might be a single point, a rectangle or a polygon. The selection process is supported by optional rubberbands (rubberband selection) and position trackers.
QwtPicker is useful for widgets where the event handlers can't be overloaded, like for components of composite widgets. It offers alternative handlers for mouse and key events.
#include <qwt_picker.h> QwtPicker *picker = new QwtPicker(widget); picker->setTrackerMode(QwtPicker::ActiveOnly); connect(picker, SIGNAL(selected(const QwtPolygon &)), ...); // emit the position of clicks on widget picker->setSelectionFlags(QwtPicker::PointSelection | QwtPicker::ClickSelection); ... // now select rectangles picker->setSelectionFlags(QwtPicker::RectSelection | QwtPicker::DragSelection); picker->setRubberBand(QwtPicker::RectRubberBand);
The selection process uses the commands begin(), append(), move() and end(). append() adds a new point to the selection, move() changes the position of the latest point.
The commands are initiated from a small state machine (QwtPickerMachine) that translates mouse and key events. There are a couple of predefined state machines for point, rect and polygon selections. The selectionFlags() control which one should be used. It is possible to use other machines by overloading stateMachine().
The picker is active (isActive()), between begin() and end(). In active state the rubberband is displayed, and the tracker is visible in case of trackerMode is ActiveOnly or AlwaysOn.
The cursor can be moved using the arrow keys. All selections can be aborted using the abort key. (QwtEventPattern::KeyPatternCode)
enum QwtEventPattern::KeyPatternCode [inherited] |
Symbolic keyboard input codes.
Default initialization:
enum QwtEventPattern::MousePatternCode [inherited] |
Symbolic mouse input codes.
The default initialization for 3 button mice is:
The default initialization for 2 button mice is:
The default initialization for 1 button mice is:
Selection subtype for RectSelection This enum type describes the type of rectangle selections. It can be or'd with QwtPicker::RectSelectionType and QwtPicker::SelectionMode and passed to QwtPicker::setSelectionFlags().
The default value is CornerToCorner.
Controls what to do with the selected points of an active selection when the observed widget is resized.
The default value is Stretch.
Rubberband style
The default value is NoRubberBand.
Values of this enum type or'd together with a SelectionType value identifies which state machine should be used for the selection.
The default value is ClickSelection.
This enum type describes the type of a selection. It can be or'd with QwtPicker::RectSelectionType and QwtPicker::SelectionMode and passed to QwtPicker::setSelectionFlags()
The default value is NoSelection.
QwtPicker::QwtPicker | ( | QWidget * | parent | ) | [explicit] |
Constructor
Creates an picker that is enabled, but where selection flag is set to NoSelection, rubberband and tracker are disabled.
parent | Parent widget, that will be observed |
QwtPicker::QwtPicker | ( | int | selectionFlags, |
RubberBand | rubberBand, | ||
DisplayMode | trackerMode, | ||
QWidget * | parent | ||
) | [explicit] |
Constructor
selectionFlags | Or'd value of SelectionType, RectSelectionType and SelectionMode |
rubberBand | Rubberband style |
trackerMode | Tracker mode |
parent | Parent widget, that will be observed |
QwtPicker::~QwtPicker | ( | ) | [virtual] |
Destructor.
bool QwtPicker::accept | ( | QwtPolygon & | selection | ) | const [protected, virtual] |
Validate and fixup the selection.
Accepts all selections unmodified
selection | Selection to validate and fixup |
Reimplemented in QwtPlotZoomer.
void QwtPicker::append | ( | const QPoint & | pos | ) | [protected, virtual] |
Append a point to the selection and update rubberband and tracker. The appended() signal is emitted.
pos | Additional point |
Reimplemented in QwtPlotPicker.
void QwtPicker::appended | ( | const QPoint & | pos | ) | [signal] |
void QwtPicker::begin | ( | ) | [protected, virtual] |
Open a selection setting the state to active
Reimplemented in QwtPlotZoomer.
void QwtPicker::changed | ( | const QwtPolygon & | pa | ) | [signal] |
A signal emitted when the active selection has been changed. This might happen when the observed widget is resized.
pa | Changed selection |
void QwtPicker::drawRubberBand | ( | QPainter * | painter | ) | const [virtual] |
Draw a rubberband , depending on rubberBand() and selectionFlags()
painter | Painter, initialized with clip rect |
void QwtPicker::drawTracker | ( | QPainter * | painter | ) | const [virtual] |
bool QwtPicker::end | ( | bool | ok = true | ) | [protected, virtual] |
Close a selection setting the state to inactive.
The selection is validated and maybe fixed by QwtPicker::accept().
ok | If true, complete the selection and emit a selected signal otherwise discard the selection. |
Reimplemented in QwtPlotPicker, and QwtPlotZoomer.
bool QwtPicker::eventFilter | ( | QObject * | o, |
QEvent * | e | ||
) | [virtual] |
Event filter.
When isEnabled() == true all events of the observed widget are filtered. Mouse and keyboard events are translated into widgetMouse- and widgetKey- and widgetWheel-events. Paint and Resize events are handled to keep rubberband and tracker up to date.
void QwtEventPattern::initKeyPattern | ( | ) | [inherited] |
Set default mouse patterns.
void QwtEventPattern::initMousePattern | ( | int | numButtons | ) | [inherited] |
Set default mouse patterns, depending on the number of mouse buttons
numButtons | Number of mouse buttons ( <= 3 ) |
bool QwtPicker::isActive | ( | ) | const |
bool QwtPicker::isEnabled | ( | ) | const |
bool QwtEventPattern::keyMatch | ( | uint | pattern, |
const QKeyEvent * | e | ||
) | const [inherited] |
Compare a key event with an event pattern.
A key event matches the pattern when both have the same key value and in the state value the same key flags (Qt::KeyButtonMask) are set.
pattern | Index of the event pattern |
e | Key event |
bool QwtEventPattern::keyMatch | ( | const KeyPattern & | pattern, |
const QKeyEvent * | e | ||
) | const [protected, virtual, inherited] |
Compare a key event with an event pattern.
A key event matches the pattern when both have the same key value and in the state value the same key flags (Qt::KeyButtonMask) are set.
pattern | Key event pattern |
e | Key event |
const QwtArray< QwtEventPattern::KeyPattern > & QwtEventPattern::keyPattern | ( | ) | const [inherited] |
Return key patterns.
QwtArray< QwtEventPattern::KeyPattern > & QwtEventPattern::keyPattern | ( | ) | [inherited] |
Return Key patterns.
bool QwtEventPattern::mouseMatch | ( | const MousePattern & | pattern, |
const QMouseEvent * | e | ||
) | const [protected, virtual, inherited] |
Compare a mouse event with an event pattern.
A mouse event matches the pattern when both have the same button value and in the state value the same key flags(Qt::KeyButtonMask) are set.
pattern | Mouse event pattern |
e | Mouse event |
bool QwtEventPattern::mouseMatch | ( | uint | pattern, |
const QMouseEvent * | e | ||
) | const [inherited] |
Compare a mouse event with an event pattern.
A mouse event matches the pattern when both have the same button value and in the state value the same key flags(Qt::KeyButtonMask) are set.
pattern | Index of the event pattern |
e | Mouse event |
const QwtArray< QwtEventPattern::MousePattern > & QwtEventPattern::mousePattern | ( | ) | const [inherited] |
Return mouse patterns.
QwtArray< QwtEventPattern::MousePattern > & QwtEventPattern::mousePattern | ( | ) | [inherited] |
Return ,ouse patterns.
void QwtPicker::move | ( | const QPoint & | pos | ) | [protected, virtual] |
Move the last point of the selection The moved() signal is emitted.
pos | New position |
Reimplemented in QwtPlotPicker.
void QwtPicker::moved | ( | const QPoint & | pos | ) | [signal] |
A signal emitted whenever the last appended point of the selection has been moved.
pos | Position of the moved last point of the selection. |
QWidget * QwtPicker::parentWidget | ( | ) |
Return the parent widget, where the selection happens.
const QWidget * QwtPicker::parentWidget | ( | ) | const |
Return the parent widget, where the selection happens.
QRect QwtPicker::pickRect | ( | ) | const [virtual] |
Find the area of the observed widget, where selection might happen.
void QwtPicker::reset | ( | ) | [protected, virtual] |
Reset the state machine and terminate (end(false)) the selection
QwtPicker::ResizeMode QwtPicker::resizeMode | ( | ) | const |
QwtPicker::RubberBand QwtPicker::rubberBand | ( | ) | const |
QPen QwtPicker::rubberBandPen | ( | ) | const |
const QWidget * QwtPicker::rubberBandWidget | ( | ) | const [protected] |
void QwtPicker::selected | ( | const QwtPolygon & | pa | ) | [signal] |
A signal emitting the selected points, at the end of a selection.
pa | Selected points |
const QwtPolygon & QwtPicker::selection | ( | ) | const |
Return Selected points.
int QwtPicker::selectionFlags | ( | ) | const |
void QwtPicker::setEnabled | ( | bool | enabled | ) | [virtual] |
En/disable the picker.
When enabled is true an event filter is installed for the observed widget, otherwise the event filter is removed.
enabled | true or false |
void QwtEventPattern::setKeyPattern | ( | const QwtArray< KeyPattern > & | pattern | ) | [inherited] |
Change the key event patterns.
void QwtEventPattern::setKeyPattern | ( | uint | pattern, |
int | key, | ||
int | state = Qt::NoButton |
||
) | [inherited] |
Change one key pattern
pattern | Index of the pattern |
key | Key |
state | State |
void QwtEventPattern::setMousePattern | ( | const QwtArray< MousePattern > & | pattern | ) | [inherited] |
Change the mouse event patterns.
void QwtEventPattern::setMousePattern | ( | uint | pattern, |
int | button, | ||
int | state = Qt::NoButton |
||
) | [inherited] |
Change one mouse pattern
pattern | Index of the pattern |
button | Button |
state | State |
void QwtPicker::setResizeMode | ( | ResizeMode | mode | ) | [virtual] |
Set the resize mode.
The resize mode controls what to do with the selected points of an active selection when the observed widget is resized.
Stretch means the points are scaled according to the new size, KeepSize means the points remain unchanged.
The default mode is Stretch.
mode | Resize mode |
void QwtPicker::setRubberBand | ( | RubberBand | rubberBand | ) | [virtual] |
Set the rubberband style
rubberBand | Rubberband style The default value is NoRubberBand. |
void QwtPicker::setRubberBandPen | ( | const QPen & | pen | ) | [virtual] |
Set the pen for the rubberband
pen | Rubberband pen |
void QwtPicker::setSelectionFlags | ( | int | flags | ) | [virtual] |
Set the selection flags
flags | Or'd value of SelectionType, RectSelectionType and SelectionMode. The default value is NoSelection. |
Reimplemented in QwtPlotZoomer.
void QwtPicker::setTrackerFont | ( | const QFont & | font | ) | [virtual] |
Set the font for the tracker
font | Tracker font |
void QwtPicker::setTrackerMode | ( | DisplayMode | mode | ) | [virtual] |
Set the display mode of the tracker.
A tracker displays information about current position of the cursor as a string. The display mode controls if the tracker has to be displayed whenever the observed widget has focus and cursor (AlwaysOn), never (AlwaysOff), or only when the selection is active (ActiveOnly).
mode | Tracker display mode |
void QwtPicker::setTrackerPen | ( | const QPen & | pen | ) | [virtual] |
Set the pen for the tracker
pen | Tracker pen |
QwtPickerMachine * QwtPicker::stateMachine | ( | int | flags | ) | const [protected, virtual] |
Create a state machine depending on the selection flags.
void QwtPicker::stretchSelection | ( | const QSize & | oldSize, |
const QSize & | newSize | ||
) | [protected, virtual] |
Scale the selection by the ratios of oldSize and newSize The changed() signal is emitted.
oldSize | Previous size |
newSize | Current size |
QFont QwtPicker::trackerFont | ( | ) | const |
QwtPicker::DisplayMode QwtPicker::trackerMode | ( | ) | const |
QPen QwtPicker::trackerPen | ( | ) | const |
QPoint QwtPicker::trackerPosition | ( | ) | const |
QRect QwtPicker::trackerRect | ( | const QFont & | font | ) | const |
Calculate the bounding rectangle for the tracker text from the current position of the tracker
font | Font of the tracker text |
QwtText QwtPicker::trackerText | ( | const QPoint & | pos | ) | const [virtual] |
Return the label for a position.
In case of HLineRubberBand the label is the value of the y position, in case of VLineRubberBand the value of the x position. Otherwise the label contains x and y position separated by a ',' .
The format for the string conversion is "%d".
pos | Position |
Reimplemented in QwtPlotPicker.
const QWidget * QwtPicker::trackerWidget | ( | ) | const [protected] |
void QwtPicker::transition | ( | const QEvent * | e | ) | [protected, virtual] |
Passes an event to the state machine and executes the resulting commands. Append and Move commands use the current position of the cursor (QCursor::pos()).
e | Event |
void QwtPicker::updateDisplay | ( | ) | [protected, virtual] |
Update the state of rubberband and tracker label.
void QwtPicker::widgetKeyPressEvent | ( | QKeyEvent * | ke | ) | [protected, virtual] |
Handle a key press event for the observed widget.
Selections can be completely done by the keyboard. The arrow keys move the cursor, the abort key aborts a selection. All other keys are handled by the current state machine.
Reimplemented in QwtPlotZoomer.
void QwtPicker::widgetKeyReleaseEvent | ( | QKeyEvent * | ke | ) | [protected, virtual] |
Handle a key release event for the observed widget.
Passes the event to the state machine.
void QwtPicker::widgetLeaveEvent | ( | QEvent * | ) | [protected, virtual] |
Handle a leave event for the observed widget.
void QwtPicker::widgetMouseDoubleClickEvent | ( | QMouseEvent * | me | ) | [protected, virtual] |
Handle mouse double click event for the observed widget.
Empty implementation, does nothing.
void QwtPicker::widgetMouseMoveEvent | ( | QMouseEvent * | e | ) | [protected, virtual] |
Handle a mouse move event for the observed widget.
Move the last point of the selection in case of isActive() == true
void QwtPicker::widgetMousePressEvent | ( | QMouseEvent * | e | ) | [protected, virtual] |
Handle a mouse press event for the observed widget.
Begin and/or end a selection depending on the selection flags.
void QwtPicker::widgetMouseReleaseEvent | ( | QMouseEvent * | e | ) | [protected, virtual] |
Handle a mouse relase event for the observed widget.
End a selection depending on the selection flags.
Reimplemented in QwtPlotZoomer.
void QwtPicker::widgetWheelEvent | ( | QWheelEvent * | e | ) | [protected, virtual] |
Handle a wheel event for the observed widget.
Move the last point of the selection in case of isActive() == true