Improve new text item continuity.

SignalMessaging/Views/ImageEditor/ImageEditorCanvasView.swift

@@ -489,13 +489,15 @@ public class ImageEditorCanvasView: UIView {
         // I don't think we need to enable allowsFontSubpixelQuantization
         // or set truncationMode.
 
-        // This text needs to be rendered at a scale that reflects the sceen scaling
+        // This text needs to be rendered at a scale that reflects:
-        // AND the item's scaling.
+        //
-        layer.contentsScale = UIScreen.main.scale * item.scaling
+        // * The screen scaling (so that text looks sharp on Retina devices.
+        // * The item's scaling (so that text doesn't become blurry as you make it larger).
+        // * Model transform (so that text doesn't become blurry as you zoom the content).
+        layer.contentsScale = UIScreen.main.scale * item.scaling * transform.scaling
 
         // TODO: Min with measured width.
         let maxWidth = imageFrame.size.width * item.unitWidth
-//        let maxWidth = viewSize.width * item.unitWidth
 
         let maxSize = CGSize(width: maxWidth, height: CGFloat.greatestFiniteMagnitude)
         // TODO: Is there a more accurate way to measure text in a CATextLayer?

SignalMessaging/Views/ImageEditor/ImageEditorTextItem.swift

@@ -101,10 +101,20 @@ public class ImageEditorTextItem: ImageEditorItem {
     }
 
     @objc
-    public class func empty(withColor color: ImageEditorColor, unitWidth: CGFloat, fontReferenceImageWidth: CGFloat) -> ImageEditorTextItem {
+    public class func empty(withColor color: ImageEditorColor,
+                            unitWidth: CGFloat,
+                            fontReferenceImageWidth: CGFloat,
+                            scaling: CGFloat,
+                            rotationRadians: CGFloat) -> ImageEditorTextItem {
         // TODO: Tune the default font size.
         let font = UIFont.boldSystemFont(ofSize: 30.0)
-        return ImageEditorTextItem(text: "", color: color, font: font, fontReferenceImageWidth: fontReferenceImageWidth, unitWidth: unitWidth)
+        return ImageEditorTextItem(text: "",
+                                   color: color,
+                                   font: font,
+                                   fontReferenceImageWidth: fontReferenceImageWidth,
+                                   unitWidth: unitWidth,
+                                   rotationRadians: rotationRadians,
+                                   scaling: scaling)
     }
 
     @objc
@@ -148,6 +158,19 @@ public class ImageEditorTextItem: ImageEditorItem {
                                    scaling: newScaling)
     }
 
+    @objc
+    public func copy(withUnitCenter newUnitCenter: CGPoint, unitWidth newUnitWidth: CGFloat) -> ImageEditorTextItem {
+        return ImageEditorTextItem(itemId: itemId,
+                                   text: text,
+                                   color: color,
+                                   font: font,
+                                   fontReferenceImageWidth: fontReferenceImageWidth,
+                                   unitCenter: newUnitCenter,
+                                   unitWidth: newUnitWidth,
+                                   rotationRadians: rotationRadians,
+                                   scaling: scaling)
+    }
+
     public override func outputScale() -> CGFloat {
         return scaling
     }

SignalMessaging/Views/ImageEditor/ImageEditorTextViewController.swift

@@ -104,6 +104,8 @@ public class ImageEditorTextViewController: OWSViewController, VAlignTextViewDel
 
     private let textItem: ImageEditorTextItem
 
+    private let isNewItem: Bool
+
     private let maxTextWidthPoints: CGFloat
 
     private let textView = VAlignTextView(alignment: .center)
@@ -117,10 +119,12 @@ public class ImageEditorTextViewController: OWSViewController, VAlignTextViewDel
     init(delegate: ImageEditorTextViewControllerDelegate,
          model: ImageEditorModel,
          textItem: ImageEditorTextItem,
+         isNewItem: Bool,
          maxTextWidthPoints: CGFloat) {
         self.delegate = delegate
         self.model = model
         self.textItem = textItem
+        self.isNewItem = isNewItem
         self.maxTextWidthPoints = maxTextWidthPoints
         self.canvasView = ImageEditorCanvasView(model: model,
                                                 itemIdsToIgnore: [textItem.itemId])
@@ -176,6 +180,7 @@ public class ImageEditorTextViewController: OWSViewController, VAlignTextViewDel
         })
 
         configureTextView()
+        textView.addRedBorder()
 
         self.view.layoutMargins = UIEdgeInsets(top: 16, left: 20, bottom: 16, right: 20)
 
@@ -245,7 +250,33 @@ public class ImageEditorTextViewController: OWSViewController, VAlignTextViewDel
     }
 
     private func completeAndDismiss() {
-        self.delegate?.textEditDidComplete(textItem: textItem, text: textView.text, color: paletteView.selectedValue)
+        var newTextItem = textItem
+
+        if isNewItem {
+            let view = self.canvasView.gestureReferenceView
+            let viewBounds = view.bounds
+
+            // Ensure continuity of the new text item's location
+            // with its apparent location in this text editor.
+            let locationInView = view.convert(textView.bounds.center, from: textView)
+            let textCenterImageUnit = ImageEditorCanvasView.locationImageUnit(forLocationInView: locationInView,
+                                                                              viewBounds: viewBounds,
+                                                                              model: model,
+                                                                              transform: model.currentTransform())
+
+            // Same, but for size.
+            let imageFrame = ImageEditorCanvasView.imageFrame(forViewSize: viewBounds.size,
+                                                              imageSize: model.srcImageSizePixels,
+                                                              transform: model.currentTransform())
+            let unitWidth = textView.width() / imageFrame.width
+
+            newTextItem = textItem.copy(withUnitCenter: textCenterImageUnit, unitWidth: unitWidth)
+        }
+
+        // Hide the text view immediately to avoid animation glitches in the dismiss transition.
+        textView.isHidden = true
+
+        self.delegate?.textEditDidComplete(textItem: newTextItem, text: textView.text, color: paletteView.selectedValue)
 
         self.dismiss(animated: false) {
             // Do nothing.

SignalMessaging/Views/ImageEditor/ImageEditorView.swift

@@ -146,11 +146,19 @@ public class ImageEditorView: UIView {
         let textWidthPoints = viewSize.width * ImageEditorTextItem.kDefaultUnitWidth
         let textWidthUnit = textWidthPoints / imageFrame.size.width
 
+        // New items should be aligned "upright", so they should have the _opposite_
+        // of the current transform rotation.
+        let rotationRadians = -model.currentTransform().rotationRadians
+        // Similarly, the size of the text item shuo
+        let scaling = 1 / model.currentTransform().scaling
+
         let textItem = ImageEditorTextItem.empty(withColor: currentColor,
                                                  unitWidth: textWidthUnit,
-                                                 fontReferenceImageWidth: imageFrame.size.width)
+                                                 fontReferenceImageWidth: imageFrame.size.width,
+                                                 scaling: scaling,
+                                                 rotationRadians: rotationRadians)
 
-        edit(textItem: textItem)
+        edit(textItem: textItem, isNewItem: true)
     }
 
     @objc func didTapDone(sender: UIButton) {
@@ -178,7 +186,7 @@ public class ImageEditorView: UIView {
             return
         }
 
-        edit(textItem: textItem)
+        edit(textItem: textItem, isNewItem: false)
     }
 
     // MARK: - Pinch Gesture
@@ -408,7 +416,7 @@ public class ImageEditorView: UIView {
 
     // MARK: - Edit Text Tool
 
-    private func edit(textItem: ImageEditorTextItem) {
+    private func edit(textItem: ImageEditorTextItem, isNewItem: Bool) {
         Logger.verbose("")
 
         // TODO:
@@ -418,6 +426,7 @@ public class ImageEditorView: UIView {
         let textEditor = ImageEditorTextViewController(delegate: self,
                                                        model: model,
                                                        textItem: textItem,
+                                                       isNewItem: isNewItem,
                                                        maxTextWidthPoints: maxTextWidthPoints)
         self.delegate?.imageEditor(presentFullScreenView: textEditor,
                                    isTransparent: false)

SignalMessaging/categories/UIView+OWS.swift

@@ -202,6 +202,10 @@ public extension CGPoint {
                        y: Swift.max(y, value.y))
     }
 
+    public var length: CGFloat {
+        return sqrt(x * x + y * y)
+    }
+
     public static let unit: CGPoint = CGPoint(x: 1.0, y: 1.0)
 
     public static let unitMidpoint: CGPoint = CGPoint(x: 0.5, y: 0.5)