CanvasUi: adding 1:1 zoom with hotkeys, matching Photoshop

Author: andrewfb

include/cinder/CanvasUi.h

@@ -144,6 +144,8 @@ class CI_API CanvasUi {
 	void zoomIn( bool disableAnimation = false );
 	//! Zoom out by one step
 	void zoomOut( bool disableAnimation = false );
+	//! Set zoom to 1.0 and offset to 0.0
+	void viewOnetoOne( bool disableAnimation = false );
 
 	//! Set custom viewport \a viewport rectangle in window coordinates
 	void setCustomViewport( const Rectf& viewport );
@@ -228,9 +230,11 @@ class CI_API CanvasUi {
 	void setHotkeysZoomIn( const std::vector<HotkeyBinding>& hotkeys );
 	//! Set \a hotkeys for zoom out
 	void setHotkeysZoomOut( const std::vector<HotkeyBinding>& hotkeys );
-	//! Set \a hotkeys for reset zoom
+	//! Set \a hotkeys for reset zoom, fitting to window for bounded and equivalent to one-to-one for unbounded
 	void setHotkeysReset( const std::vector<HotkeyBinding>& hotkeys );
-
+	//! Set \a hotkeys for setting zoom and pan to 1:1
+	void setHotkeysOneToOne( const std::vector<HotkeyBinding>& hotkeys );
+	
 	//! Allow panning content outside viewport bounds (auto-disables constrainZoomToContent when enabled). Default is \c false.
 	void setAllowPanOutside( bool allow );
 	//! Check if content can be panned outside viewport bounds. Default is \c false
@@ -286,6 +290,7 @@ class CI_API CanvasUi {
 	std::vector<HotkeyBinding>		mHotkeysZoomIn;
 	std::vector<HotkeyBinding>		mHotkeysZoomOut;
 	std::vector<HotkeyBinding>		mHotkeysReset;
+	std::vector<HotkeyBinding>		mHotkeysOneToOne;
 	std::vector<MouseButtonBinding> mPanMouseButtons;
 
 	// Animation state
@@ -332,4 +337,4 @@ class CI_API CanvasUi {
 	bool  matchesPanMouseButton( const app::MouseEvent& event, const std::vector<MouseButtonBinding>& buttons ) const;
 };
 
-} // namespace cinder
+} // namespace cinder

src/cinder/CanvasUi.cpp

@@ -34,11 +34,11 @@ CanvasUi::CanvasUi()
 {
 	// Set default hotkeys
 	using namespace app;
-#if defined( CINDER_MSW )
+#if defined( CINDER_MSW ) || defined( CINDER_MAC )
 	// On Windows, use ACCEL_DOWN (which maps to CTRL_DOWN)
 	unsigned int modifier = KeyEvent::ACCEL_DOWN;
 #else
-	// On Linux/Mac, use CTRL_DOWN directly for consistency with Windows behavior
+	// On Linux, use CTRL_DOWN directly for consistency with Windows behavior
 	unsigned int modifier = KeyEvent::CTRL_DOWN;
 #endif
 	mHotkeysZoomIn.emplace_back( KeyEvent::KEY_PLUS, modifier );
@@ -51,6 +51,9 @@ CanvasUi::CanvasUi()
 	mHotkeysReset.emplace_back( KeyEvent::KEY_0, modifier );
 	mHotkeysReset.emplace_back( KeyEvent::KEY_KP0, modifier );
 
+	mHotkeysOneToOne.emplace_back( KeyEvent::KEY_1, modifier );
+	mHotkeysOneToOne.emplace_back( KeyEvent::KEY_KP1, modifier );
+	
 	// Set default pan mouse buttons: Alt+Left, Middle, or Right mouse
 	mPanMouseButtons.emplace_back( app::MouseEvent::LEFT_DOWN, app::MouseEvent::ALT_DOWN );
 	mPanMouseButtons.emplace_back( app::MouseEvent::MIDDLE_DOWN, 0 );
@@ -307,6 +310,20 @@ void CanvasUi::zoomOut( bool disableAnimation )
 	}
 }
 
+void CanvasUi::viewOnetoOne( bool disableAnimation )
+{
+	vec2 centerViewport = mViewport.getSize() * 0.5f; // Center of viewport in viewport-local coordinates
+
+	// Calculate the zoom factor needed to reach 1.0
+	float zoomFactor = 1.0f / mZoom;
+
+	if( mAnimationEnabled && ! disableAnimation ) {
+		startZoomAnimation( zoomFactor, centerViewport );
+	} else {
+		zoomByStep( zoomFactor, centerViewport );
+	}
+}
+
 // Helper to set zoom and position with proper constraints
 void CanvasUi::setZoomAndPosition( float newZoom, const vec2& newPositionViewport )
 {
@@ -633,6 +650,12 @@ void CanvasUi::keyDown( app::KeyEvent& event )
 	else if( matchesHotkey( event, mHotkeysReset ) ) {
 		if( isBounded() )
 			fitAll();
+		else
+			viewOnetoOne();
+		event.setHandled();
+	}
+	else if( matchesHotkey( event, mHotkeysOneToOne ) ) {
+		viewOnetoOne();
 		event.setHandled();
 	}
 }
@@ -777,6 +800,10 @@ void CanvasUi::setHotkeysReset( const std::vector<HotkeyBinding>& hotkeys )
 	mHotkeysReset = hotkeys;
 }
 
+void CanvasUi::setHotkeysOneToOne( const std::vector<HotkeyBinding>& hotkeys )
+{
+	mHotkeysOneToOne = hotkeys;
+}
 
 bool CanvasUi::matchesHotkey( const app::KeyEvent& event, const std::vector<HotkeyBinding>& hotkeys ) const
 {
@@ -908,4 +935,4 @@ void CanvasUi::setAllowPanOutside( bool allow )
 		mConstrainZoomToContent = false;
 }
 
-} // namespace cinder
+} // namespace cinder