PinchEventMonitor.h File Reference

Platform-specific render-pane pinch gesture capture. On macOS this installs a local magnify-event monitor and feeds synthetic zoom scroll events into the existing editor queue. More...

#include <vector>
#include "donner/editor/RenderPaneGesture.h"

Include dependency graph for PinchEventMonitor.h:

Namespaces
namespace	donner
	Top-level Donner namespace, which is split into different sub-namespaces such as donner::svg and donner::css.

Functions
double	donner::editor::PinchMagnificationToScrollDelta (double magnification, double wheelZoomStep)
	Convert an NSEvent magnification delta into the equivalent vertical scroll delta for the existing wheel-zoom model.
bool	donner::editor::InstallPinchEventMonitor (GLFWwindow *window, std::vector< RenderPaneScrollEvent > *events, double wheelZoomStep)
	Install the native pinch monitor for the editor window.

Detailed Description

Platform-specific render-pane pinch gesture capture. On macOS this installs a local magnify-event monitor and feeds synthetic zoom scroll events into the existing editor queue.

Function Documentation

InstallPinchEventMonitor()

bool donner::editor::InstallPinchEventMonitor ( GLFWwindow * window, std::vector< RenderPaneScrollEvent > * events, double wheelZoomStep )

nodiscard

Install the native pinch monitor for the editor window.

On macOS this registers an NSEventMaskMagnify local monitor that pushes synthetic zoom-marked scroll events into events. Other platforms provide a stub that returns false.

Parameters

window	GLFW window that owns the render pane.
events	Scroll-event queue drained by the render pane each frame.
wheelZoomStep	Multiplicative zoom step per +1.0 scroll unit.

Returns

True if the native monitor was installed or was already active for this process.

PinchMagnificationToScrollDelta()

double donner::editor::PinchMagnificationToScrollDelta ( double magnification, double wheelZoomStep )

nodiscard

Convert an NSEvent magnification delta into the equivalent vertical scroll delta for the existing wheel-zoom model.

The classifier interprets zoom as pow(wheelZoomStep, scrollDeltaY). Pinch magnification instead reports the multiplicative zoom delta as 1 + magnification, so this helper computes the inverse mapping.

Parameters

magnification	Cocoa magnification delta (e.g. 0.2 for 20% pinch-out).
wheelZoomStep	Multiplicative zoom step per +1.0 scroll unit.

Returns

Synthetic scrollDelta.y that yields the same zoom factor, or 0.0 for degenerate inputs.