Merge pull request #61 from Rinzwind/canvas-background-formset

Extend AeCanvas to support setting a FormSet as background

src/Alexandrie-Cairo-Tests/AeFilesystemResources.extension.st

@@ -12,6 +12,12 @@ AeFilesystemResources class >> imagesDirectory [
 	^ self testsDirectory / 'images'
 ]
 
+{ #category : #'*Alexandrie-Cairo-Tests' }
+AeFilesystemResources class >> removeIcon2xPNG [
+
+	^ self imagesDirectory / 'removeIcon-2x.png'
+]
+
 { #category : #'*Alexandrie-Cairo-Tests' }
 AeFilesystemResources class >> removeIconPNG [
 

src/Alexandrie-Canvas-Tests/AeCanvasTest.class.st

@@ -307,6 +307,33 @@ AeCanvasTest >> renderForm [
 	^ aeCanvas
 ]
 
+{ #category : #tests }
+AeCanvasTest >> renderFormSet [
+
+	| aeCanvas aForm aFormSet |
+
+	SystemVersion current major >= 12 ifFalse: [ self skip ]. "Earlier versions do not have FormSet"
+
+	aeCanvas := AeCanvas newFor: ((AeCairoImageSurface extent: (60@20) * 2) deviceScale: 2 asPoint; yourself).
+	aeCanvas clear: Color paleGreen.
+
+	aForm := Form fromFileNamed: AeFilesystemResources removeIcon2xPNG.
+	aFormSet := FormSet extent: aForm extent // 2 depth: aForm depth forms: { aForm }.
+
+	aeCanvas pathScale: ((aeCanvas extent / aeCanvas deviceScale) / aFormSet extent) asFloatPoint.
+	aeCanvas pathFactory: [ :cairoContext |
+		"Tip: Use another path to clip the form"
+		cairoContext rectangleTo: aFormSet extent ].
+
+	aeCanvas
+		setBackgroundWithFormSet: aFormSet
+		alpha: 1.0.
+	aeCanvas setBorderOff.
+	aeCanvas drawFigure.
+
+	^ aeCanvas
+]
+
 { #category : #private }
 AeCanvasTest >> renderGlyphs: aCairoGlyphsArray scaledFont: aCairoScaledFont on: aeCanvas [
 

src/Alexandrie-Canvas/AeCanvas.class.st

@@ -32,6 +32,7 @@ Class {
 		'hasBackground',
 		'borderWidth',
 		'formToCairoSurfaceCache',
+		'formSetToCairoSurfaceCache',
 		'backgroundAlpha',
 		'cairoSurface',
 		'backgroundSourceBlock',
@@ -414,6 +415,15 @@ AeCanvas >> initializeCaches [
 		factory: [ :form | AeCairoImageSurface fromForm: form ];
 		yourself.
 
+	formSetToCairoSurfaceCache := LRUCache new
+		maximumWeight: 400;
+		factory: [ :formSet |
+			| scale |
+			scale := self deviceScale max rounded.
+			(AeCairoImageSurface fromForm: (formSet asFormAtScale: scale))
+				deviceScale: scale asPoint;
+				yourself ];
+		yourself.
 ]
 
 { #category : #initialization }
@@ -693,6 +703,17 @@ AeCanvas >> setBackgroundWithForm: aForm alpha: aDouble [
 
 ]
 
+{ #category : #'API - background' }
+AeCanvas >> setBackgroundWithFormSet: aFormSet alpha: aDouble [
+
+	self
+		setBackgroundWith: [ 
+			| aCairoSurface |
+			aCairoSurface := formSetToCairoSurfaceCache at: aFormSet.
+			cairoContext sourceSurface: aCairoSurface x: 0.0 y: 0.0 ]
+ 		alpha: aDouble
+]
+
 { #category : #'API - border' }
 AeCanvas >> setBorderBlock: aBlockClosure [