feat: improve thumbnails performance (closes #4)

lwouis · Aug 18, 2019 · 509e5e0 · 509e5e0
1 parent 2fa3f24
commit 509e5e0
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Showing 2 changed files with 40 additions and 37 deletions.
diff --git a/alt-tab-swindler/Application.swift b/alt-tab-swindler/Application.swift
@@ -3,7 +3,7 @@ import Foundation
 
 let cellBorderWidth: CGFloat = 5
 let thumbnailHeight: CGFloat = 250
-let thumbnailMaxWidth = 400
+let thumbnailMaxWidth: CGFloat = 400
 let thumbnailEstimatedWidth: CGFloat = 140 + cellBorderWidth * 2
 let textHeight: CGFloat = 20
 let cellHeight = thumbnailHeight + textHeight + cellBorderWidth * 2
@@ -85,6 +85,7 @@ class Application: NSApplication, NSApplicationDelegate, NSWindowDelegate, NSCol
     var openWindows: [OpenWindow] = []
     var workItems: [DispatchWorkItem] = []
     var isFirstSummon: Bool = true
+    var appIsBeingUsed: Bool = false
 
     func applicationDidFinishLaunching(_ aNotification: Notification) {
         ensureAccessibilityCheckboxIsChecked()
@@ -104,6 +105,12 @@ class Application: NSApplication, NSApplicationDelegate, NSWindowDelegate, NSCol
         listenToGlobalKeyboardEvents(delegate: self)
     }
 
+    func applicationDidBecomeActive(_ notification: Notification) {
+        if (!self.appIsBeingUsed) {
+            self.focusSelectedWindow()
+        }
+    }
+
     func makeCollectionView() {
         let layout = CollectionViewLeftFlowLayout()
         layout.estimatedItemSize = NSSize(width: thumbnailEstimatedWidth, height: thumbnailHeight)
@@ -194,7 +201,8 @@ class Application: NSApplication, NSApplicationDelegate, NSWindowDelegate, NSCol
     }
 
     func collectionView(_ collectionView: NSCollectionView, layout collectionViewLayout: NSCollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> NSSize {
-        return NSSize(width: thumbnails[indexPath.item].size.width + cellBorderWidth * 2, height: cellHeight)
+        let (width, height) = computeDownscaledSize(thumbnails[indexPath.item])
+        return NSSize(width: CGFloat(width) + cellBorderWidth * 2, height: CGFloat(height) + textHeight + cellBorderWidth * 2)
     }
 
     func cellWithStep(_ step: Int) -> Int {
@@ -215,29 +223,34 @@ class Application: NSApplication, NSApplicationDelegate, NSWindowDelegate, NSCol
                 self.showWindow()
             }
             workItems.append(workItem)
-            DispatchQueue.main.asyncAfter(deadline: .now() + 0.200, execute: workItem)
+            DispatchQueue.main.asyncAfter(deadline: .now() + 0.2, execute: workItem)
         } else {
             highlightThumbnail(step)
         }
     }
 
-    private func showWindow() {
+    func showWindow() {
         self.window!.makeKeyAndOrderFront(nil)
         NSRunningApplication.current.activate(options: [.activateIgnoringOtherApps, .activateAllWindows])
     }
 
-    func keyUpAlt() {
-        debugPrint("alt up")
-        if NSRunningApplication.current.isActive {
-            isFirstSummon = true
-            workItems.forEach({ $0.cancel() })
-            workItems.removeAll()
+    func focusSelectedWindow() {
+        workItems.forEach({ $0.cancel() })
+        workItems.removeAll()
+        if openWindows.count > selectedOpenWindow {
             openWindows[selectedOpenWindow].focus()
         }
     }
 
+    func keyDownAlt() {
+        debugPrint("alt down")
+        computeOpenWindows()
+        selectedOpenWindow = 0
+    }
+
     func keyDownAltTab() {
         debugPrint("alt+tab down")
+        appIsBeingUsed = true
         selectOtherCell(1)
     }
 
@@ -246,9 +259,12 @@ class Application: NSApplication, NSApplicationDelegate, NSWindowDelegate, NSCol
         selectOtherCell(-1)
     }
 
-    func keyDownAlt() {
-        debugPrint("alt down")
-        computeOpenWindows()
-        selectedOpenWindow = 0
+    func keyUpAlt() {
+        debugPrint("alt up")
+        if appIsBeingUsed {
+            focusSelectedWindow()
+        }
+        appIsBeingUsed = false
+        isFirstSummon = true
     }
 }
diff --git a/alt-tab-swindler/WindowManager.swift b/alt-tab-swindler/WindowManager.swift
@@ -22,31 +22,18 @@ class OpenWindow {
 
 func computeWindowThumbnail(_ cgId: CGWindowID) -> NSImage {
     let windowImage = CGWindowListCreateImage(.null, .optionIncludingWindow, cgId, [.boundsIgnoreFraming, .bestResolution])
-    let imageRatio = CGFloat(windowImage!.width) / CGFloat(windowImage!.height)
-    let thumbnailWidth = Int(floor(thumbnailHeight * imageRatio))
     let image = NSImage(cgImage: windowImage!, size: NSSize(width: windowImage!.width, height: windowImage!.height))
-    if (thumbnailWidth <= thumbnailMaxWidth) {
-        return resize(image, thumbnailWidth, Int(thumbnailHeight))
-    } else {
-        return resize(image, thumbnailMaxWidth, Int(floor(CGFloat(thumbnailMaxWidth) / imageRatio)))
-    }
+    return image
 }
 
-func resize(_ image: NSImage, _ w: Int, _ h: Int) -> NSImage {
-    let destSize = NSMakeSize(CGFloat(w), CGFloat(h))
-    let newImage = NSImage(size: destSize)
-    newImage.lockFocus()
-    image.draw(
-            in: NSMakeRect(0, 0, destSize.width, destSize.height),
-            from: NSMakeRect(0, 0, image.size.width, image.size.height),
-            operation: NSCompositingOperation.copy,
-            fraction: CGFloat(1),
-            respectFlipped: true,
-            hints: [NSImageRep.HintKey.interpolation: NSImageInterpolation.high.rawValue]
-    )
-    newImage.unlockFocus()
-    newImage.size = destSize
-    return NSImage(data: newImage.tiffRepresentation!)!
+func computeDownscaledSize(_ image: NSImage) -> (Int, Int) {
+    let imageRatio = image.size.width / image.size.height
+    let thumbnailWidth = Int(floor(thumbnailHeight * imageRatio))
+    if (thumbnailWidth <= Int(thumbnailMaxWidth)) {
+        return (thumbnailWidth, Int(thumbnailHeight))
+    } else {
+        return (Int(thumbnailMaxWidth), Int(floor(thumbnailMaxWidth / imageRatio)))
+    }
 }
 
 func cgMakeshiftId(_ window: NSDictionary) -> (String, pid_t, CGWindowID, String) {
@@ -99,7 +86,7 @@ func AXUIElementCopyAttributeValue<T>(_ element: AXUIElement, _ attribute: Strin
 }
 
 func AXValueGetValue<T>(_ element: AXUIElement, _ attribute: String, _ target: T, _ type: AXValueType) -> T? {
-    if let a = AXUIElementCopyAttributeValue(element,  attribute,  AXValue.self) {
+    if let a = AXUIElementCopyAttributeValue(element, attribute, AXValue.self) {
         var value = target
         AXValueGetValue(a, type, &value)
         return value