Show and switch between multiple images

LayerX/AppDelegate.swift

@@ -23,9 +23,6 @@ class AppDelegate: NSObject, NSApplicationDelegate {
 	var isLockIconHiddenWhileLocked = false {
 		didSet { viewController.lockIconImageView.isHidden = window.isMovable || isLockIconHiddenWhileLocked }
 	}
-	var isSizeHidden = false {
-		didSet { viewController.sizeTextField.isHidden = isSizeHidden }
-	}
 
 	func applicationDidFinishLaunching(_ aNotification: Notification) {
 		if let window = NSApp.windows.first as? MCWIndow {
@@ -48,10 +45,10 @@ fileprivate enum ArrowTag: Int {
 extension AppDelegate {
 
 	private var originalSize: NSSize {
-		viewController.imageView.image?.size ?? defaultSize
+		viewController.imageSize ?? defaultSize
 	}
 
-	private func resizeAspectFit(calculator: (_ original: CGFloat, _ current: CGFloat) -> CGFloat) {
+	func resizeAspectFit(calculator: (_ original: CGFloat, _ current: CGFloat) -> CGFloat) {
 		let originalSize = self.originalSize
 		let width = calculator(originalSize.width, window.frame.size.width)
 		let height = width / originalSize.width * originalSize.height
@@ -82,15 +79,11 @@ extension AppDelegate {
 	}
 
 	@IBAction func increaseTransparency(_ sender: AnyObject) {
-		var alpha = viewController.imageView.alphaValue
-		alpha -= 0.1
-		viewController.imageView.alphaValue = max(alpha, 0.05)
+		viewController.changeTransparency(by: -0.1)
 	}
 
 	@IBAction func reduceTransparency(_ sender: AnyObject) {
-		var alpha = viewController.imageView.alphaValue
-		alpha += 0.1
-		viewController.imageView.alphaValue = min(alpha, 1.0)
+		viewController.changeTransparency(by: 0.1)
 	}
 
 	func getPasteboardImage() -> NSImage? {
@@ -112,16 +105,10 @@ extension AppDelegate {
 
 		return nil
 	}
-	
+
 	@IBAction func paste(_ sender: AnyObject) {
 		guard let image = getPasteboardImage() else { return }
-		let rep = image.representations[0]
-		viewController.imageView.image = image
-		let size = NSMakeSize(CGFloat(rep.pixelsWide), CGFloat(rep.pixelsHigh))
-		window.resizeTo(size, animated: true)
-		viewController.sizeTextField.isHidden = false
-		viewController.placeholderTextField.isHidden = true
-
+		viewController.updateCurrentImage(image)
 	}
 
 	@IBAction func toggleLockWindow(_ sender: AnyObject) {
@@ -164,7 +151,7 @@ extension AppDelegate {
 	@IBAction func toggleSizeVisibility(_ sender: AnyObject) {
 		let menuItem = sender as! NSMenuItem
 		menuItem.state = menuItem.state == .on ? .off : .on
-		isSizeHidden = menuItem.state == .on
+		viewController.isSizeHidden = menuItem.state == .on
 	}
 
 	@IBAction func moveAround(_ sender: AnyObject) {
@@ -197,10 +184,6 @@ extension AppDelegate {
 			window.collectionBehavior = [.managed, .moveToActiveSpace]
 		}
 	}
-
-	func validateMenuItem(_ menuItem: NSMenuItem) -> Bool {
-		return viewController.imageView.image != nil
-	}
 }
 
 // MARK: - Helper

LayerX/Base.lproj/Main.storyboard

@@ -303,7 +303,15 @@
                                 <rect key="frame" x="454" y="243" width="16" height="17"/>
                                 <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" refusesFirstResponder="YES" sendsActionOnEndEditing="YES" alignment="center" title="0" drawsBackground="YES" id="Mmp-Eh-bBs">
                                     <font key="font" metaFont="system"/>
-                                    <color key="textColor" name="textBackgroundColor" catalog="System" colorSpace="catalog"/>
+                                    <color key="textColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
+                                    <color key="backgroundColor" red="0.0" green="0.0" blue="0.0" alpha="0.59999999999999998" colorSpace="calibratedRGB"/>
+                                </textFieldCell>
+                            </textField>
+                            <textField hidden="YES" wantsLayer="YES" horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="kNK-da-5FA">
+                                <rect key="frame" x="10" y="244" width="30" height="16"/>
+                                <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" refusesFirstResponder="YES" sendsActionOnEndEditing="YES" alignment="center" title="⌘ 1" drawsBackground="YES" id="N44-hk-hFy">
+                                    <font key="font" metaFont="system"/>
+                                    <color key="textColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
                                     <color key="backgroundColor" red="0.0" green="0.0" blue="0.0" alpha="0.59999999999999998" colorSpace="calibratedRGB"/>
                                 </textFieldCell>
                             </textField>
@@ -327,12 +335,14 @@
                         <constraints>
                             <constraint firstAttribute="bottom" secondItem="3I3-1H-JKb" secondAttribute="bottom" constant="10" id="64H-0g-nnO"/>
                             <constraint firstItem="8Vs-Az-CYd" firstAttribute="centerY" secondItem="m2S-Jp-Qdl" secondAttribute="centerY" id="6fI-na-pdX"/>
+                            <constraint firstItem="kNK-da-5FA" firstAttribute="top" secondItem="m2S-Jp-Qdl" secondAttribute="top" constant="10" id="9LJ-n2-2gE"/>
                             <constraint firstItem="8Vs-Az-CYd" firstAttribute="centerX" secondItem="m2S-Jp-Qdl" secondAttribute="centerX" id="RwW-eB-OYh"/>
                             <constraint firstItem="JAT-ZL-8HB" firstAttribute="top" secondItem="m2S-Jp-Qdl" secondAttribute="top" constant="10" id="WnK-c6-NWw"/>
                             <constraint firstItem="pOu-B0-2Yd" firstAttribute="top" secondItem="m2S-Jp-Qdl" secondAttribute="top" id="aC7-xh-2BR"/>
                             <constraint firstItem="pOu-B0-2Yd" firstAttribute="leading" secondItem="m2S-Jp-Qdl" secondAttribute="leading" id="lhy-17-EcM"/>
                             <constraint firstAttribute="trailing" secondItem="pOu-B0-2Yd" secondAttribute="trailing" id="qbm-Dq-jeg"/>
                             <constraint firstAttribute="bottom" secondItem="pOu-B0-2Yd" secondAttribute="bottom" id="r2U-99-hj5"/>
+                            <constraint firstItem="kNK-da-5FA" firstAttribute="leading" secondItem="m2S-Jp-Qdl" secondAttribute="leading" constant="10" id="tUz-La-jPF"/>
                             <constraint firstAttribute="trailing" secondItem="3I3-1H-JKb" secondAttribute="trailing" constant="10" id="und-pJ-9Mz"/>
                             <constraint firstAttribute="trailing" secondItem="JAT-ZL-8HB" secondAttribute="trailing" constant="10" id="xlU-hc-l09"/>
                         </constraints>
@@ -342,6 +352,7 @@
                         <outlet property="lockIconImageView" destination="3I3-1H-JKb" id="Nka-rj-tDO"/>
                         <outlet property="placeholderTextField" destination="8Vs-Az-CYd" id="env-Po-Bb7"/>
                         <outlet property="sizeTextField" destination="JAT-ZL-8HB" id="vIP-80-PVG"/>
+                        <outlet property="tabTextField" destination="kNK-da-5FA" id="bpw-Fo-3hM"/>
                     </connections>
                 </viewController>
                 <customObject id="rPt-NT-nkU" userLabel="First Responder" customClass="NSResponder" sceneMemberID="firstResponder"/>

LayerX/ViewController.swift

@@ -10,20 +10,33 @@ import Cocoa
 
 class ViewController: NSViewController {
 
-	@IBOutlet weak var imageView: MCDragAndDropImageView!
+	@IBOutlet private weak var imageView: MCDragAndDropImageView!
 	@IBOutlet weak var sizeTextField: NSTextField!
 	@IBOutlet weak var placeholderTextField: NSTextField!
 	@IBOutlet weak var lockIconImageView: NSImageView!
+	@IBOutlet weak var tabTextField: NSTextField!
+
+	var isSizeHidden = false {
+		didSet { updateTextFieldVisibility() }
+	}
+
+	private var currentTab = 1 // Falls in range 1...9
+	private var tabImages = [Int: NSImage]()
 
 	override var acceptsFirstResponder: Bool {
 		return true
 	}
 
 	lazy var trackingArea: NSTrackingArea = {
-		let options: NSTrackingArea.Options = [.activeAlways, .mouseEnteredAndExited]
-		return NSTrackingArea(rect: self.view.bounds, options: options, owner: self, userInfo: nil)
+		let options: NSTrackingArea.Options = [.activeAlways, .mouseEnteredAndExited, .inVisibleRect]
+		return NSTrackingArea(rect: view.bounds, options: options, owner: self, userInfo: nil)
 	}()
 
+	private var isMouseInView: Bool {
+		guard let window = view.window else { return false }
+		return view.isMousePoint(window.mouseLocationOutsideOfEventStream, in: view.frame)
+	}
+
 	deinit {
 		NotificationCenter.default.removeObserver(self)
 	}
@@ -49,54 +62,114 @@ class ViewController: NSViewController {
 		NotificationCenter.default.addObserver(self, selector: #selector(windowDidResize(_:)), name: NSWindow.didResizeNotification, object: appDelegate().window)
 
 		view.addTrackingArea(trackingArea)
+
+		NSEvent.addLocalMonitorForEvents(matching: .keyDown) { [weak self] event -> NSEvent? in
+			if event.modifierFlags.contains(.command), event.characters?.count == 1 {
+				if event.characters?.lowercased() == "w" {
+					self?.updateCurrentImage(nil)
+					return nil
+				} else if let digit = event.characters.flatMap(Int.init), digit != 0 {
+					self?.selectTab(digit)
+					return nil
+				}
+			}
+
+			return event
+		}
 	}
 
-	@objc func fadeOutSizeTextField() {
-		let transition = CATransition()
-		sizeTextField.layer?.add(transition, forKey: "fadeOut")
-		sizeTextField.layer?.opacity = 0
+	// MARK: Tabs management
+
+	var imageSize: NSSize? {
+		guard let image = imageView.image else { return nil }
+		let pixelSize = image.representations.first.map { NSSize(width: $0.pixelsWide, height: $0.pixelsHigh) }
+		return pixelSize ?? image.size
+	}
+
+	func selectTab(_ tab: Int) {
+		currentTab = tab
+		tabTextField.stringValue = "⌘ \(tab)"
+
+		let image = tabImages[currentTab]
+		showImage(image)
+
+		if image != nil {
+			appDelegate().resizeAspectFit(calculator: { $1 })
+		}
+	}
+
+	func updateCurrentImage(_ image: NSImage?) {
+		let hadNoImages = tabImages.isEmpty
+
+		tabImages[currentTab] = image
+		showImage(image)
+
+		if image != nil {
+			appDelegate().resizeAspectFit(calculator: { hadNoImages ? $0 : $1 })
+		}
+	}
+
+	private func showImage(_ image: NSImage?) {
+		imageView.image = image
+
+		tabTextField.isHidden = false
+		updateTextFieldVisibility()
+
+		tabTextField.fadeIn()
+		if !isMouseInView {
+			tabTextField.fadeOutAfterDelay()
+		}
+	}
+
+	private func updateTextFieldVisibility() {
+		let hasImage = imageView.image != nil
+
+		sizeTextField.isHidden = !hasImage || isSizeHidden
+		placeholderTextField.isHidden = hasImage
+	}
+
+	// MARK: Actions
+
+	func changeTransparency(by diff: CGFloat) {
+		imageView.alphaValue = min(max(imageView.alphaValue + diff, 0.05), 1.0)
 	}
 
 	@objc func windowDidResize(_ notification: Notification) {
 		let window = notification.object as! NSWindow
 		let size = window.frame.size
 		sizeTextField.stringValue = "\(Int(size.width))x\(Int(size.height))"
-		sizeTextField.layer?.opacity = 1
+		sizeTextField.fadeIn()
 
-		NSObject.cancelPreviousPerformRequests(withTarget: self, selector: #selector(ViewController.fadeOutSizeTextField), object: nil)
-		perform(#selector(ViewController.fadeOutSizeTextField), with: nil, afterDelay: 2)
+		if !isMouseInView {
+			sizeTextField.fadeOutAfterDelay()
+		}
 	}
 
 	// MARK: Mouse events
 
 	override func scrollWheel(with theEvent: NSEvent) {
-		guard let _ = imageView.image else { return }
+		guard imageView.image != nil else { return }
 
-		let delta = theEvent.deltaY * 0.005;
-		var alpha = imageView.alphaValue - delta
-		alpha = min(alpha, 1)
-		alpha = max(alpha, 0.05)
-		imageView.alphaValue = alpha
+		let delta = theEvent.deltaY * 0.005
+		changeTransparency(by: -delta)
 	}
 
 	override func mouseEntered(with theEvent: NSEvent) {
-		sizeTextField.layer?.opacity = 1
+		sizeTextField.fadeIn()
+		tabTextField.fadeIn()
 	}
 
 	override func mouseExited(with theEvent: NSEvent) {
-		fadeOutSizeTextField()
+		sizeTextField.fadeOut()
+		tabTextField.fadeOut()
 	}
 }
 
 // MARK: - MCDragAndDropImageViewDelegate
 
 extension ViewController: MCDragAndDropImageViewDelegate {
 	func dragAndDropImageViewDidDrop(_ imageView: MCDragAndDropImageView) {
-
-		sizeTextField.isHidden = false
-		placeholderTextField.isHidden = true
-
-		appDelegate().actualSize(nil)
+		updateCurrentImage(imageView.image)
 	}
 }
 
@@ -107,3 +180,28 @@ class MCMovableView: NSView{
 		return true
 	}
 }
+
+// MARK: - Hiding text
+
+fileprivate extension NSView {
+
+	func fadeIn() {
+		NSObject.cancelPreviousPerformRequests(withTarget: self, selector: #selector(fadeOut), object: nil)
+
+		layer?.opacity = 1
+	}
+
+	@objc func fadeOut() {
+		// Fade out is always animated
+		let transition = CATransition()
+		layer?.add(transition, forKey: "fadeOut")
+		layer?.opacity = 0
+	}
+
+	func fadeOutAfterDelay() {
+		NSObject.cancelPreviousPerformRequests(withTarget: self, selector: #selector(fadeOut), object: nil)
+
+		perform(#selector(fadeOut), with: nil, afterDelay: 2)
+	}
+
+}

README.md

@@ -14,7 +14,8 @@ Support Mac OS X 10.10 or later.
 - [x] Keyboard Shortcuts
 - [x] Adjust transparency  
 - [x] Lock images
-- [X] Aspect ratio scaling
+- [x] Aspect ratio scaling
+- [x] Switching between multiple images
 
 # Keyboard Shortcuts
 
@@ -23,6 +24,8 @@ Support Mac OS X 10.10 or later.
 | Key | Action |
 |:--- |:---    |
 |`⌘ V`| Paste image or file from clipboard. |
+|`⌘ 1-9`| Switch between image tabs. |
+|`⌘ W`| Remove image assigned to the current tab. |
 
 ### Scale