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#include <ArmarXGui/gui-plugins/StatechartViewerPlugin/view/GraphicsViewZoom.h>
Signals | |
void | moved () |
void | zoomed () |
Public Member Functions | |
void | gentle_zoom (double factor) |
QGraphicsView * | getView () const |
Graphics_view_zoom (QGraphicsView *view) | |
void | set_modifiers (Qt::KeyboardModifiers modifiers) |
void | set_zoom_factor_base (double value) |
This class adds ability to zoom QGraphicsView using mouse wheel. The point under cursor remains motionless while it's possible.
Note that it becomes not possible when the scene's size is not large enough comparing to the viewport size. QGraphicsView centers the picture when it's smaller than the view. And QGraphicsView's scrolls boundaries don't allow to put any picture point at any viewport position.
When the user starts scrolling, this class remembers original scene position and keeps it until scrolling is completed. It's better than getting original scene position at each scrolling step because that approach leads to position errors due to before-mentioned positioning restrictions.
When zommed using scroll, this class emits zoomed() signal.
Usage:
new Graphics_view_zoom(view);
The object will be deleted automatically when the view is deleted.
You can set keyboard modifiers used for zooming using set_modified(). Zooming will be performed only on exact match of modifiers combination. The default modifier is Ctrl.
You can change zoom velocity by calling set_zoom_factor_base(). Zoom coefficient is calculated as zoom_factor_base^angle_delta (see QWheelEvent::angleDelta). The default zoom factor base is 1.0015.
Definition at line 64 of file GraphicsViewZoom.h.
Graphics_view_zoom | ( | QGraphicsView * | view | ) |
Definition at line 42 of file GraphicsViewZoom.cpp.
void gentle_zoom | ( | double | factor | ) |
Definition at line 51 of file GraphicsViewZoom.cpp.
QGraphicsView * getView | ( | ) | const |
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signal |
void set_modifiers | ( | Qt::KeyboardModifiers | modifiers | ) |
void set_zoom_factor_base | ( | double | value | ) |
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signal |