added exceptions to setting magnification, first implementation of se…

…tMagnfication through rect and point, and allowed negative values to be passed to scaleUnitSize
darlinghq · Feb 16, 2024 · 0ae4f4c · 0ae4f4c
1 parent 1ab8aac
commit 0ae4f4c
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Showing 4 changed files with 41 additions and 32 deletions.
diff --git a/.vscode/settings.json b/.vscode/settings.json
diff --git a/AppKit/NSScrollView.m b/AppKit/NSScrollView.m
@@ -872,19 +872,23 @@ - (void) allowsMagnification: (BOOL) value {
     _allowsMagnification = value;
 }
 
-- (void) setMagnification: (CGFloat) value {
-    _magnification = value;
-}
-
 - (void) setMaxMagnification: (CGFloat) value {
     if (value >= _minMagnification) {
         _maxMagnification = value;
+    } else {
+        [NSException raise: NSInvalidArgumentException
+                    format: @"maxMagnification (%.3f) must be greater than or equal to minMagnification (%.3f).",
+                            value, _minMagnification];
     }
 }
 
 - (void) setMinMagnification: (CGFloat) value {
     if (value <= _maxMagnification) {
         _minMagnification = value;
+    } else {
+        [NSException raise: NSInvalidArgumentException
+                    format: @"minMagnification (%.3f) must be less than or equal to maxMagnification (%.3f).",
+                            value, _maxMagnification];
     }
 }
 
@@ -1114,13 +1118,36 @@ - (void) resizeSubviewsWithOldSize: (NSSize) oldSize {
         [self _horizontalScroll: _horizontalScroller];
 }
 
+- (void) setMagnification:(CGFloat) magnification 
+         centeredAtPoint:(NSPoint) point {
+    // scale the content view centered at the given point
+    NSRect frame = [_clipView frame];
+    NSSize scaledSize = NSMakeSize(frame.size.width*magnification, frame.size.height*magnification);
+    NSPoint centeredOrigin = NSMakePoint(point.x - (newSize.width/2), point.y - (newSize.height/2));
+    [_clipView setFrame:NSMakeRect(centeredOrigin.x, centeredOrigin.y, scaledSize.width, scaledSize.height)];
+
+    // clip the resulting magnification value to min and max magnification
+    magnification = MAX(_minMagnification, magnification);
+    magnification = MIN(_maxMagnification, magnification);
+
+    self._magnification = magnification;
+}
+
 - (void) magnifyToFitRect: (NSRect) rect {
-    NSUnimplementedMethod();
-    /*
-        todo
-        Magnifies the content view proportionally such that the given rectangle fits centered in the scroll view.
-        The resulting magnification value is clipped to the minMagnification and maxMagnification values
-    */
+    if (_allowsMagnification) {
+        // find magnification value needed to scale the content view to the given rectangle without morphing
+        CGFloat widthMagnification = NSWidth(_clipView.bounds) / NSWidth(rect);
+        CGFloat heightMagnification = NSHeight(_clipView.bounds) / NSHeight(rect);
+        CGFloat magnification = MIN(widthMagnification, heightMagnification);
+
+        // The resulting magnification value is clipped to the min/max magnification
+        magnification = MAX(_minMagnification, magnification);
+        magnification = MIN(_maxMagnification, magnification);
+
+        (NSPoint) point = NSMakePoint(NSMidX(rect), NSMidY(rect));
+
+        [_clipView setMagnification:magnification centeredAtPoint:point];
+    }
 }
 
 @end
diff --git a/AppKit/NSView.m b/AppKit/NSView.m
@@ -646,21 +646,10 @@ - (BOOL) postsBoundsChangedNotifications {
     return _postsNotificationOnBoundsChange;
 }
 
-// todo after implementing this, i need to implement magnification support in nsscrollview
 - (void) scaleUnitSquareToSize: (NSSize) size {
     if (size.width != 1.0 || size.height != 1.0) {
-        if (size.width < 0) {
-            size.width = 0;
-        }
-        if (size.height < 0) {
-            size.height = 0;
-        }
-        if (_bounds == nil) {
-            // todo set _bounds. would _bounds ever by nil? need to look into that
-            // _bounds = [NSAffineTransform new]
-        }
+        // todo what if width or height is zero?
 
-        // todo need to get scaleXBy in here, located in darling-foundation
         [_bounds scaleXBy: size.width yBy: size.height];
 
         _bounds.origin.x = _bounds.origin.x / size.width;
@@ -671,8 +660,7 @@ - (void) scaleUnitSquareToSize: (NSSize) size {
         isRotatedOrScaledFromBase = YES;
 
         /* code from gnustep
-        todo flag should be located in appkit/include/nsview.h
-
+        todo
         if (_coordinates_valid)
             {
             (*invalidateImp)(self, invalidateSel);

diff --git a/AppKit/include/AppKit/NSScrollView.h b/AppKit/include/AppKit/NSScrollView.h
@@ -151,11 +151,12 @@ APPKIT_EXPORT NSString *const NSScrollViewDidLiveScrollNotification;
 - (void) setMaxMagnification: (CGFloat) value;
 - (void) setAllowsMagnification: (BOOL) value;
 - (void) setMaxMagnification: (CGFloat) value;
-- (void) setMagnification: (CGFloat) value;
 - (void) minMagnification: (CGFloat) value;
 
 - (void) tile;
 - (void) reflectScrolledClipView: (NSClipView *) clipView;
+- (void) setMagnification:(CGFloat) magnification 
+         centeredAtPoint:(NSPoint) point;
 - (void) magnifyToFitRect: (NSRect) rect;
 
 @end