Merge pull request #16 from igorkulman/ratio-fix

Correctly resizing wallpapers

Sources/ChangeMenuBarColor/Commands/Gradient.swift

@@ -41,7 +41,7 @@ final class Gradient: Command, ParsableCommand {
             return nil
         }
 
-        guard let resizedWallpaper = wallpaper.resized(to: screen.size) else {
+        guard let resizedWallpaper = wallpaper.crop(size: screen.size) else {
             print("Cannot not resize provided wallpaper to screen size".red)
             return nil
         }

Sources/ChangeMenuBarColor/Commands/SolidColor.swift

@@ -33,7 +33,7 @@ final class SolidColor: Command, ParsableCommand {
             return nil
         }
 
-        guard let resizedWallpaper = wallpaper.resized(to: screen.size) else {
+        guard let resizedWallpaper = wallpaper.crop(size: screen.size) else {
             print("Cannot not resize provided wallpaper to screen size".red)
             return nil
         }

Sources/ChangeMenuBarColor/Extensions/NSImage+Extensions.swift

@@ -15,29 +15,97 @@ extension NSImage {
         return self.cgImage(forProposedRect: &rect, context: nil, hints: nil)
     }
 
-    func resized(to newSize: NSSize) -> NSImage? {
-        guard let bitmapRep = NSBitmapImageRep(bitmapDataPlanes: nil, pixelsWide: Int(newSize.width), pixelsHigh: Int(newSize.height), bitsPerSample: 8, samplesPerPixel: 4, hasAlpha: true, isPlanar: false, colorSpaceName: .calibratedRGB, bytesPerRow: 0, bitsPerPixel: 0) else {
-            print("Cannot create bitmap image for resizing".red)
-            return nil
-        }
-
-        bitmapRep.size = newSize
-        NSGraphicsContext.saveGraphicsState()
-        NSGraphicsContext.current = NSGraphicsContext(bitmapImageRep: bitmapRep)
-        draw(in: NSRect(x: 0, y: 0, width: newSize.width, height: newSize.height), from: .zero, operation: .copy, fraction: 1.0)
-        NSGraphicsContext.restoreGraphicsState()
-
-        let resizedImage = NSImage(size: newSize)
-        resizedImage.addRepresentation(bitmapRep)
-        return resizedImage
-    }
-
     var jpgData: Data? {
         guard let tiffRepresentation = tiffRepresentation, let bitmapImage = NSBitmapImageRep(data: tiffRepresentation) else {
             print("Cannot create data from bitmap image".red)
             return nil
         }
 
         return bitmapImage.representation(using: .jpeg, properties: [:])
-    }    
+    }
+
+    var height: CGFloat {
+        return self.size.height
+    }
+
+    var width: CGFloat {
+        return self.size.width
+    }
+
+    func copy(size: NSSize) -> NSImage? {
+        // Create a new rect with given width and height
+        let frame = NSMakeRect(0, 0, size.width, size.height)
+
+        // Get the best representation for the given size.
+        guard let rep = self.bestRepresentation(for: frame, context: nil, hints: nil) else {
+            return nil
+        }
+
+        // Create an empty image with the given size.
+        let img = NSImage(size: size)
+
+        // Set the drawing context and make sure to remove the focus before returning.
+        img.lockFocus()
+        defer { img.unlockFocus() }
+
+        // Draw the new image
+        if rep.draw(in: frame) {
+            return img
+        }
+
+        // Return nil in case something went wrong.
+        return nil
+    }
+
+    func resizeWhileMaintainingAspectRatioToSize(size: NSSize) -> NSImage? {
+        let newSize: NSSize
+
+        let widthRatio  = size.width / self.width
+        let heightRatio = size.height / self.height
+
+        if widthRatio > heightRatio {
+            newSize = NSSize(width: floor(self.width * widthRatio), height: floor(self.height * widthRatio))
+        } else {
+            newSize = NSSize(width: floor(self.width * heightRatio), height: floor(self.height * heightRatio))
+        }
+
+        return self.copy(size: newSize)
+    }
+
+    func crop(size: NSSize) -> NSImage? {
+        // Resize the current image, while preserving the aspect ratio.
+        guard let resized = self.resizeWhileMaintainingAspectRatioToSize(size: size) else {
+            return nil
+        }
+        // Get some points to center the cropping area.
+        let x = floor((resized.width - size.width) / 2)
+        let y = floor((resized.height - size.height) / 2)
+
+        // Create the cropping frame.
+        let frame = NSMakeRect(x, y, size.width, size.height)
+
+        // Get the best representation of the image for the given cropping frame.
+        guard let rep = resized.bestRepresentation(for: frame, context: nil, hints: nil) else {
+            return nil
+        }
+
+        // Create a new image with the new size
+        let img = NSImage(size: size)
+
+        img.lockFocus()
+        defer { img.unlockFocus() }
+
+        if rep.draw(in: NSMakeRect(0, 0, size.width, size.height),
+                    from: frame,
+                    operation: NSCompositingOperation.copy,
+                    fraction: 1.0,
+                    respectFlipped: false,
+                    hints: [:]) {
+            // Return the cropped image.
+            return img
+        }
+
+        // Return nil in case anything fails.
+        return nil
+    }
 }