Grid cell background fix (#298)

* Fixed background color of gridView to be same a container editorview

* Fixed tests

* Made BackgroundColorInheriting observable on attachment view

* Made GridView BackgroundColorObserving

Author: rajdeep

Diff for: Proton/Sources/Swift/Attachment/Attachment.swift

@@ -27,6 +27,11 @@ public protocol DynamicBoundsProviding: AnyObject {
     func sizeFor(attachment: Attachment, containerSize: CGSize, lineRect: CGRect) -> CGSize
 }
 
+/// Denotes an `Attachment`content view  that observes  background color changes in `containerEditorView`
+public protocol BackgroundColorObserving where Self: UIView {
+    func containerEditor(_ editor: EditorView, backgroundColorUpdated color: UIColor?, oldColor: UIColor?)
+}
+
 /// Describes an object capable of providing offsets for the `Attachment`. The value is used to offset the `Attachment` when rendered alongside the text. This may
 /// be used to align the content baselines in `Attachment` content to that of it's container's content baselines.
 /// - Note:
@@ -598,6 +603,10 @@ open class Attachment: NSTextAttachment, BoundsObserving {
         guard let view = view,
             view.superview == nil else { return }
         editorView.richTextView.addSubview(view)
+        if let backgroundColorInheriting = self.contentView as? BackgroundColorObserving,
+           editorView.backgroundColor != nil {
+            backgroundColorInheriting.containerEditor(editorView, backgroundColorUpdated: editorView.backgroundColor, oldColor: nil)
+        }
 
         if var editorContentView = contentView as? EditorContentView,
            editorContentView.delegate == nil {

Diff for: Proton/Sources/Swift/Editor/EditorView.swift

@@ -440,6 +440,10 @@ open class EditorView: UIView {
     public override var backgroundColor: UIColor? {
         didSet {
             richTextView.backgroundColor = backgroundColor
+            if backgroundColor != oldValue {
+                updateBackgroundInheritingViews(color: backgroundColor, oldColor: backgroundColor)
+            }
+            delegate?.editor(self, didChangeBackgroundColor: backgroundColor, oldColor: oldValue)
         }
     }
 
@@ -1278,6 +1282,13 @@ open class EditorView: UIView {
         textViewDelegate.textViewDidChange?(richTextView)
         return true
     }
+
+    private func updateBackgroundInheritingViews(color: UIColor?, oldColor: UIColor?) {
+        let backgroundColorInheritingViews = attributedText.attachmentRanges.compactMap{ $0.attachment.contentView as? BackgroundColorObserving }
+        backgroundColorInheritingViews.forEach {
+            $0.containerEditor(self, backgroundColorUpdated: color, oldColor: oldColor)
+        }
+    }
 }
 
 extension EditorView {

Diff for: Proton/Sources/Swift/Editor/EditorViewDelegate.swift

@@ -134,6 +134,8 @@ public protocol EditorViewDelegate: AnyObject {
     /// - Returns: `true` to delete, else `false`
     /// - Note: If either this or`Attachment`s property of `selectBeforeDelete` is `true`, the attachment will be shown as selected on backspace.
     func editor(_ editor: EditorView, shouldSelectAttachmentOnBackspace attachment: Attachment) -> Bool?
+
+    func editor(_ editor: EditorView, didChangeBackgroundColor color: UIColor?, oldColor: UIColor?)
 }
 
 public extension EditorViewDelegate {
@@ -155,4 +157,5 @@ public extension EditorViewDelegate {
     func editor(_ editor: EditorView, shouldSelectAttachmentOnBackspace attachment: Attachment) -> Bool? {
         return nil
     }
+    func editor(_ editor: EditorView, didChangeBackgroundColor color: UIColor?, oldColor: UIColor?) { }
 }

Diff for: Proton/Sources/Swift/Grid/View/GridCell.swift

@@ -101,6 +101,7 @@ protocol GridCellDelegate: AnyObject {
     func cell(_ cell: GridCell, didChangeSelectionAt range: NSRange, attributes: [NSAttributedString.Key : Any], contentType: EditorContent.Name)
     func cell(_ cell: GridCell, didReceiveKey key: EditorKey, at range: NSRange)
     func cell(_ cell: GridCell, didChangeSelected isSelected: Bool)
+    func cell(_ cell: GridCell, didChangeBackgroundColor color: UIColor?, oldColor: UIColor?)
 }
 
 /// Denotes a cell in the `GridView`
@@ -122,6 +123,13 @@ open class GridCell {
     /// Frame of the cell within `GridView`
     public internal(set) var frame: CGRect = .zero
 
+    public var backgroundColor: UIColor? = nil {
+        didSet {
+            contentView.backgroundColor = backgroundColor
+            editor.backgroundColor = backgroundColor
+        }
+    }
+
     private var selectionView: SelectionView?
     private let editorInitializer: EditorInitializer
 
@@ -280,6 +288,13 @@ open class GridCell {
         }
     }
 
+    func updateBackgroundColorFromParent(color: UIColor?, oldColor: UIColor?) {
+        // check for same color is required. In absence of that, the rendering causes
+        // collapsed cells to still show text even though cell is collapsed
+        guard backgroundColor == oldColor, backgroundColor != color else { return }
+        backgroundColor = color
+    }
+
     private func assertEditorSetupCompleted() {
         guard editorSetupComplete == false,
               ignoresOptimizedInit == false else {
@@ -322,6 +337,7 @@ open class GridCell {
         editor.translatesAutoresizingMaskIntoConstraints = false
         editor.boundsObserver = self
         editor.delegate = self
+
         contentView.addSubview(editor)
 
         NSLayoutConstraint.activate([
@@ -367,6 +383,11 @@ extension GridCell: EditorViewDelegate {
     public func editor(_ editor: EditorView, didReceiveKey key: EditorKey, at range: NSRange) {
         delegate?.cell(self, didReceiveKey: key, at: range)
     }
+
+    public func editor(_ editor: EditorView, didChangeBackgroundColor color: UIColor?, oldColor: UIColor?) {
+        contentView.backgroundColor = color
+        delegate?.cell(self, didChangeBackgroundColor: color, oldColor: oldColor)
+    }
 }
 
 extension GridCell: Equatable {

Diff for: Proton/Sources/Swift/Grid/View/GridContentView.swift

@@ -43,6 +43,8 @@ protocol GridContentViewDelegate: AnyObject {
     func gridContentView(_ gridContentView: GridContentView, didDeleteColumnAt index: Int)
 
     func gridContentView(_ gridContentView: GridContentView, shouldChangeColumnWidth proposedWidth: CGFloat, for columnIndex: Int) -> Bool
+
+    func gridContentView(_ gridContentView: GridContentView, cell: GridCell, didChangeBackgroundColor color: UIColor?, oldColor: UIColor?)
 }
 
 class GridContentView: UIScrollView {
@@ -68,6 +70,12 @@ class GridContentView: UIScrollView {
 
     private(set) var selectedCells: [GridCell] = [GridCell]()
 
+    override var backgroundColor: UIColor? {
+        didSet {
+            cells.forEach { $0.updateBackgroundColorFromParent(color: backgroundColor, oldColor: oldValue) }
+        }
+    }
+
     var numberOfColumns: Int {
         grid.numberOfColumns
     }
@@ -447,6 +455,10 @@ extension GridContentView: GridCellDelegate {
         gridContentViewDelegate?.gridContentView(self, didChangeSelectionAt: range, attributes: attributes, contentType: contentType, in: cell)
     }
 
+    func cell(_ cell: GridCell, didChangeBackgroundColor color: UIColor?, oldColor: UIColor?) {
+        gridContentViewDelegate?.gridContentView(self, cell: cell, didChangeBackgroundColor: color, oldColor: oldColor)
+    }
+
     func cell(_ cell: GridCell, didChangeBounds bounds: CGRect) {
         guard  let row = cell.rowSpan.first else { return }
         if grid.rowHeights.count > row,

Diff for: Proton/Sources/Swift/Grid/View/GridView.swift

@@ -262,6 +262,12 @@ public class GridView: UIView {
         fatalError("init(coder:) has not been implemented")
     }
 
+    public override var backgroundColor: UIColor? {
+        didSet {
+            gridView.backgroundColor = backgroundColor
+        }
+    }
+
     private func setup() {
         gridView.translatesAutoresizingMaskIntoConstraints = false
         leadingShadowView.translatesAutoresizingMaskIntoConstraints = false
@@ -655,6 +661,9 @@ extension GridView: GridContentViewDelegate {
     func gridContentView(_ gridContentView: GridContentView, shouldChangeColumnWidth proposedWidth: CGFloat, for columnIndex: Int) -> Bool {
         delegate?.gridView(self, shouldChangeColumnWidth: proposedWidth, for: columnIndex) ?? true
     }
+
+    func gridContentView(_ gridContentView: GridContentView, cell: GridCell, didChangeBackgroundColor color: UIColor?, oldColor: UIColor?) {
+    }
 }
 
 class CellHandleButton: UIButton {
@@ -674,3 +683,9 @@ class CellHandleButton: UIButton {
 }
 
 extension GridView: AsyncDeferredRenderable { }
+
+extension GridView: BackgroundColorObserving {
+    public func containerEditor(_ editor: EditorView, backgroundColorUpdated color: UIColor?, oldColor: UIColor?) {
+        backgroundColor = color
+    }
+}

Diff for: Proton/Tests/Attachments/GridViewAttachment.swift

@@ -48,3 +48,9 @@ extension GridView: AttachmentViewIdentifying {
 
     public var type: AttachmentType { .block }
 }
+
+extension GridView: BackgroundColorObserving {
+    public func containerEditor(_ editor: EditorView, backgroundColorUpdated color: UIColor?, oldColor: UIColor?) {
+        backgroundColor = color
+    }
+}

Diff for: Proton/Tests/Grid/GridViewAttachmentSnapshotTests.swift

@@ -50,6 +50,37 @@ class GridViewAttachmentSnapshotTests: SnapshotTestCase {
         assertSnapshot(matching: viewController.view, as: .image, record: recordMode)
     }
 
+    func testRendersGridViewAttachmentWithContainerBackgroundColor() {
+        let viewController = EditorTestViewController()
+        let editor = viewController.editor
+        let config = GridConfiguration(
+            columnsConfiguration: [
+                GridColumnConfiguration(width: .fixed(100)),
+                GridColumnConfiguration(width: .fractional(100))
+            ],
+            rowsConfiguration: [
+                GridRowConfiguration(initialHeight: 40),
+                GridRowConfiguration(initialHeight: 40),
+            ])
+        let attachment = GridViewAttachment(config: config)
+
+        editor.backgroundColor = .lightGray
+        editor.replaceCharacters(in: .zero, with: "Some text in editor")
+        editor.insertAttachment(in: editor.textEndRange, attachment: attachment)
+        editor.replaceCharacters(in: editor.textEndRange, with: "Text after grid")
+
+        let cell = attachment.view.cellAt(rowIndex: 0, columnIndex: 0)
+        cell?.editor.attributedText = NSAttributedString(string: "Test\nNew line\nMore text")
+        cell?.backgroundColor = .white
+
+        viewController.render(size: CGSize(width: 300, height: 225))
+        assertSnapshot(matching: viewController.view, as: .image, record: recordMode)
+
+        editor.backgroundColor = .darkGray
+        viewController.render(size: CGSize(width: 300, height: 225))
+        assertSnapshot(matching: viewController.view, as: .image, record: recordMode)
+    }
+
     func testRendersGridViewAttachmentWithConstrainedFixedWidth() {
         let viewController = EditorTestViewController()
         let editor = viewController.editor

Diff for: Proton/Tests/Grid/Mocks/MockGridCellDelegate.swift

@@ -30,6 +30,7 @@ class MockGridCellDelegate: GridCellDelegate {
     var onDidChangeSelection: ((GridCell, NSRange, [NSAttributedString.Key : Any], EditorContent.Name) -> Void)?
     var onDidReceiveKey: ((GridCell, EditorKey, NSRange) -> Void)?
     var onDidChangeSelected: ((GridCell, Bool) -> Void)?
+    var onDidChangeBackgroundColor: ((GridCell, UIColor?, UIColor?) -> Void)?
 
 
     func cell(_ cell: GridCell, didChangeBounds bounds: CGRect) {
@@ -59,4 +60,8 @@ class MockGridCellDelegate: GridCellDelegate {
     func cell(_ cell: GridCell, didChangeSelected isSelected: Bool) {
         onDidChangeSelected?(cell, isSelected)
     }
+
+    func cell(_ cell: GridCell, didChangeBackgroundColor color: UIColor?, oldColor: UIColor?) {
+        onDidChangeBackgroundColor?(cell, color, oldColor)
+    }
 }