Patch support for symbol overrides

What a mess. Not sure it works in call cases, but good start

LippyPatcher.m

@@ -11,6 +11,42 @@
 
 @implementation LippyPatcher
 
+// FIXME: <dmitry.rodionov> Lippy won't hold a strong reference to its activeTextOverride, so here we are, keeping it alive just like this
+static NSArray *kSelectedTextOverrides = nil;
+
+static NSValue *MSLayerAbsoluteRect(id /* __kindof MSLayer */ layer) {
+    id parent = [layer parentObject];
+    NSRect frame = [[layer valueForKeyPath:@"frame.rect"] rectValue];
+    NSRect absoluteFrame = [parent convertRect:frame toCoordinateSpace:nil];
+    return [NSValue valueWithPoint:absoluteFrame.origin];
+};
+
+static NSArray *MSSymbolInstanceSelectedTextOverrides(id /* MSSymbolInstance */ instance) {
+    // We filter for the currently selected text overrides on the given symbol instance
+    NSSet *selection = [[instance valueForKeyPath:@"documentData.currentPage.currentSelection"]
+                        filteredSetUsingPredicate:[NSPredicate predicateWithBlock:^BOOL(id item, id _Nullable bindings) {
+        return [item valueForKey:@"primarySelection"] == instance && [item canOverrideTextStringValue];
+    }]];
+    NSMutableArray *result = [NSMutableArray arrayWithCapacity:selection.count];
+    for (id item in selection) {
+        // FIXME: <dmitry.rodionov> this should've been a proper object, but who cares as long as the interface is the same
+        [result addObject:@{
+            @"selectionID": @"stringValue",
+            @"availableOverride": @{
+                @"overrideValue": [item valueForKeyPath:@"selectedLayer.stringValue"] ?: @"",
+                @"overridePoint": [item textStringOverridePoint],
+                @"affectedLayer": @{
+                    @"rect": ({
+                        NSRect absoluteRect = [[item valueForKey:@"absoluteAlignmentRect"] rectValue];
+                        @([instance convertRect:absoluteRect fromCoordinateSpace:nil]);
+                    })
+                }
+            }
+        }];
+    }
+    return result;
+};
+
 + (void)load
 {
     NSBundle *originalLippyBundle = ^NSBundle *(void) {
@@ -26,26 +62,37 @@ + (void)load
         return;
     }
 
+    // See kSelectedOverrides definition at the top of this file
+    Class LippyMainViewController = NSClassFromString(@"LippyMainViewController");
+    SEL showEditorForContextSel = NSSelectorFromString(@"showEditorForContext:");
+    [LippyMainViewController aspect_hookSelector:showEditorForContextSel withOptions:AspectPositionBefore usingBlock:^() {
+        kSelectedTextOverrides = nil;
+    } error:nil];
+
     Class MSDocument = NSClassFromString(@"MSDocument");
     NSCAssert(MSDocument != nil, @"");
     [MSDocument aspect_hookSelector:@selector(valueForKeyPath:) withOptions:AspectPositionInstead usingBlock:^(id<AspectInfo> aspectInfo, NSString *keyPath) {
         NSInvocation *invocation = aspectInfo.originalInvocation;
-        // Replace the key path in [MSDocument valueForKeyPath:@"selectedLayers.layers"] to just "selectedLayers"
+        // -[MSDocument selectedLayers] no longer contains symbol instances for which one of the overrides
+        // is selected, so we use a different API (which also works for plain selection)
         if ([keyPath isEqualToString:@"selectedLayers.layers"]) {
-            NSString *patchedKeyPath = @"selectedLayers";
-            [invocation setArgument:&patchedKeyPath atIndex:2];
+            NSArray *primarySelection = [[aspectInfo.instance valueForKeyPath:@"documentData.currentPage.currentSelection.primarySelection"] allObjects];
+            void *result = (__bridge void *)primarySelection;
+            [invocation setReturnValue:&result];
+            return;
         }
         // Lippy's Sketch version number parser has a common flaw: it doesn't support 3-digit major versions,
         // which makes it believe it's running on e.g. Sketch 10.0 instead of 100, which in turn makes it
         // choose a wrong API to use in this case. We fix it back to the correct one
+        // TODO: <dmitry.rodionov> patch -[Lippy sketchVersion] directly to return a correct value?
         if ([keyPath isEqualToString:@"currentContentViewController.contentDrawView"]) {
             NSString *patchedKeyPath = @"currentContentViewController.canvasView";
             [invocation setArgument:&patchedKeyPath atIndex:2];
         }
         [invocation invoke];
     } error:nil];
 
-    // Fix +[Lippy colorFromHex:] to use modern Sketch API
+    // Fix +[Lippy colorFromHex:] to use an up-to-date Sketch API
     Class LippyParentClass = object_getClass(NSClassFromString(@"Lippy"));
     NSCAssert(LippyParentClass != nil, @"");
     SEL colorFromHexSel = NSSelectorFromString(@"colorFromHex:");
@@ -57,34 +104,36 @@ + (void)load
         [invocation setReturnValue:&result];
     } error:nil];
 
-    // Fix -valueForKeyPath:@"absoluteRect.origin" in various classes
-    __auto_type absoluteRectFixup = ^(id<AspectInfo> aspectInfo, NSString *keyPath) {
+    // Fix absoluteRect calculation for MSTextLayers
+    Class MSTextLayer = NSClassFromString(@"MSTextLayer");
+    [MSTextLayer aspect_hookSelector:@selector(valueForKeyPath:) withOptions:AspectPositionInstead usingBlock:^(id<AspectInfo> aspectInfo, NSString *keyPath) {
         NSInvocation *invocation = aspectInfo.originalInvocation;
         [invocation invoke];
         if ([keyPath isEqualToString:@"absoluteRect.origin"]) {
-            id parent = [aspectInfo.instance parentObject];
-            NSRect frame = [[aspectInfo.instance valueForKeyPath:@"frame.rect"] rectValue];
-            NSRect absoluteFrame = [parent convertRect:frame toCoordinateSpace:nil];
-
-            NSValue *result = [NSValue valueWithPoint:absoluteFrame.origin];
+            NSValue *result = MSLayerAbsoluteRect(aspectInfo.instance);
             [invocation setReturnValue:&result];
         }
-    };
-
-    // MARK: - Text Layers
-    Class MSTextLayer = NSClassFromString(@"MSTextLayer");
-    [MSTextLayer aspect_hookSelector:@selector(valueForKeyPath:) withOptions:AspectPositionInstead usingBlock:absoluteRectFixup error:nil];
+    } error:nil];
 
-    // MARK: - Symbol Instances (WIP)
     Class MSSymbolInstance = NSClassFromString(@"MSSymbolInstance");
-    [MSSymbolInstance aspect_hookSelector:@selector(valueForKeyPath:) withOptions:AspectPositionInstead usingBlock:absoluteRectFixup error:nil];
-
-    // TODO: <dmitry.rodionov> fix [MSSymbolInstance valueForKeyPath:@"overrideContainer.selectedOverrides"]
-        // -> an array of MSOverrideRepresentation
-    // TODO: <dmitry.rodionov> fix [<text override class> valueForKeyPath:@"availableOverride.affectedLayer.rect"];
-    // TODO: <dmitry.rodionov> fix [<text override class> valueForKeyPath:@"availableOverride.overrideValue"];
+    [MSSymbolInstance aspect_hookSelector:@selector(valueForKeyPath:) withOptions:AspectPositionInstead usingBlock:^(id<AspectInfo> aspectInfo, NSString *keyPath) {
+        NSInvocation *invocation = aspectInfo.originalInvocation;
+        [invocation invoke];
 
-    // to get an override point => [activeTextOverride valueForKeyPath:@"availableOverride.overridePoint"];
+        // Fix absoluteRect calculation for MSSymbolInstances
+        if ([keyPath isEqualToString:@"absoluteRect.origin"]) {
+            NSValue *result = MSLayerAbsoluteRect(aspectInfo.instance);
+            [invocation setReturnValue:&result];
+        }
+        // Prepare an artificial array of selected overrides on the given symbol instance
+        // in a format expected by Lippy's routines
+        if ([keyPath isEqualToString:@"overrideContainer.selectedOverrides"]) {
+            // See kSelectedOverrides definition at the top of this file
+            kSelectedTextOverrides = MSSymbolInstanceSelectedTextOverrides(aspectInfo.instance);
+            void *result = (__bridge void *)kSelectedTextOverrides;
+            [invocation setReturnValue:&result];
+        }
+    } error:nil];
 }
 
 
@@ -95,5 +144,9 @@ + (id)colorWithHex:(NSString *)hex alpha:(CGFloat)alpha { return nil; }
 - (id)NSColorWithColorSpace:(CGColorSpaceRef)colorSpace { return nil; }
 - (id)parentObject { return nil; }
 - (NSRect)convertRect:(NSRect)rect toCoordinateSpace:(id)space { return NSZeroRect; }
+- (NSRect)convertRect:(NSRect)rect fromCoordinateSpace:(id)space { return NSZeroRect; }
+- (NSSet *)primarySelection { return nil; }
+- (BOOL)canOverrideTextStringValue { return NO; }
+- (id)textStringOverridePoint { return nil; }
 
 @end