Set the cursor when dragging would resize bounding box

This makes it obvious to users when clicking will resize the bounding
box, rather than creating a new one.

4 files changed, 111 insertions, 23 deletions

diff --git a/tikzit/src/gtk/GraphInputHandler.h b/tikzit/src/gtk/GraphInputHandler.h
index 61af36f..9955459 100644
--- a/tikzit/src/gtk/GraphInputHandler.h
+++ b/tikzit/src/gtk/GraphInputHandler.h
@@ -50,7 +50,7 @@ typedef enum {
     NSPoint        oldLeaderPos;
     Edge          *modifyEdge;
     NSMutableSet  *selectionBoxContents;
-    ResizeHandle   grabbedResizeHandle;
+    ResizeHandle   currentResizeHandle;
     NSPoint        oldOrigin;
 }
 
diff --git a/tikzit/src/gtk/GraphInputHandler.m b/tikzit/src/gtk/GraphInputHandler.m
index 4d77045..caaadeb 100644
--- a/tikzit/src/gtk/GraphInputHandler.m
+++ b/tikzit/src/gtk/GraphInputHandler.m
@@ -34,7 +34,7 @@ static const InputMask unionSelectMask = ShiftMask;
         leaderNode = nil;
         modifyEdge = nil;
         selectionBoxContents = [[NSMutableSet alloc] initWithCapacity:10];
-        grabbedResizeHandle = NoHandle;
+        currentResizeHandle = NoHandle;
     }
 
     return self;
@@ -94,6 +94,7 @@ static const InputMask unionSelectMask = ShiftMask;
     if (mode != m) {
         if (mode == BoundingBoxMode) {
             [renderer setBoundingBoxHandlesShown:NO];
+            [[renderer surface] setCursor:NormalCursor];
         }
         mode = m;
         [self deselectAll];
@@ -143,9 +144,9 @@ static const InputMask unionSelectMask = ShiftMask;
         }
     } else if (mode == BoundingBoxMode) {
         state = BoundingBoxState;
-        grabbedResizeHandle = [renderer boundingBoxResizeHandleAt:pos];
+        currentResizeHandle = [renderer boundingBoxResizeHandleAt:pos];
         [[self doc] startChangeBoundingBox];
-        if (grabbedResizeHandle == NoHandle) {
+        if (currentResizeHandle == NoHandle) {
             [[[self doc] graph] setBoundingBox:NSZeroRect];
             [renderer setBoundingBoxHandlesShown:NO];
         }
@@ -324,7 +325,7 @@ static const InputMask unionSelectMask = ShiftMask;
     } else if (state == BoundingBoxState) {
         Grid *grid = [renderer grid];
         Graph *graph = [[self doc] graph];
-        if (grabbedResizeHandle == NoHandle) {
+        if (currentResizeHandle == NoHandle) {
             NSRect bbox = NSRectAroundPoints(
                 [grid snapScreenPoint:dragOrigin],
                 [grid snapScreenPoint:pos]
@@ -334,9 +335,9 @@ static const InputMask unionSelectMask = ShiftMask;
             NSRect bbox = [transformer rectToScreen:[graph boundingBox]];
             NSPoint p2 = [grid snapScreenPoint:pos];
 
-            if (grabbedResizeHandle == NorthWestHandle ||
-                    grabbedResizeHandle == NorthHandle ||
-                    grabbedResizeHandle == NorthEastHandle) {
+            if (currentResizeHandle == NorthWestHandle ||
+                    currentResizeHandle == NorthHandle ||
+                    currentResizeHandle == NorthEastHandle) {
 
                     float dy = p2.y - NSMinY(bbox);
                     if (dy < bbox.size.height) {
@@ -347,9 +348,9 @@ static const InputMask unionSelectMask = ShiftMask;
                         bbox.size.height = 0;
                     }
 
-            } else if (grabbedResizeHandle == SouthWestHandle ||
-                    grabbedResizeHandle == SouthHandle ||
-                    grabbedResizeHandle == SouthEastHandle) {
+            } else if (currentResizeHandle == SouthWestHandle ||
+                    currentResizeHandle == SouthHandle ||
+                    currentResizeHandle == SouthEastHandle) {
 
                     float dy = p2.y - NSMaxY(bbox);
                     if (-dy < bbox.size.height) {
@@ -359,9 +360,9 @@ static const InputMask unionSelectMask = ShiftMask;
                     }
             }
 
-            if (grabbedResizeHandle == NorthWestHandle ||
-                    grabbedResizeHandle == WestHandle ||
-                    grabbedResizeHandle == SouthWestHandle) {
+            if (currentResizeHandle == NorthWestHandle ||
+                    currentResizeHandle == WestHandle ||
+                    currentResizeHandle == SouthWestHandle) {
 
                     float dx = p2.x - NSMinX(bbox);
                     if (dx < bbox.size.width) {
@@ -372,9 +373,9 @@ static const InputMask unionSelectMask = ShiftMask;
                         bbox.size.width = 0;
                     }
 
-            } else if (grabbedResizeHandle == NorthEastHandle ||
-                    grabbedResizeHandle == EastHandle ||
-                    grabbedResizeHandle == SouthEastHandle) {
+            } else if (currentResizeHandle == NorthEastHandle ||
+                    currentResizeHandle == EastHandle ||
+                    currentResizeHandle == SouthEastHandle) {
 
                     float dx = p2.x - NSMaxX(bbox);
                     if (-dx < bbox.size.width) {
@@ -393,6 +394,43 @@ static const InputMask unionSelectMask = ShiftMask;
         [[renderer transformer] setOrigin:newOrigin];
         [renderer invalidateGraph];
     }
+    if (mode == BoundingBoxMode && state != BoundingBoxState) {
+        ResizeHandle handle = [renderer boundingBoxResizeHandleAt:pos];
+        if (handle != currentResizeHandle) {
+            currentResizeHandle = handle;
+            Cursor c = NormalCursor;
+            switch (handle) {
+                case EastHandle:
+                    c = ResizeRightCursor;
+                    break;
+                case SouthEastHandle:
+                    c = ResizeBottomRightCursor;
+                    break;
+                case SouthHandle:
+                    c = ResizeBottomCursor;
+                    break;
+                case SouthWestHandle:
+                    c = ResizeBottomLeftCursor;
+                    break;
+                case WestHandle:
+                    c = ResizeLeftCursor;
+                    break;
+                case NorthWestHandle:
+                    c = ResizeTopLeftCursor;
+                    break;
+                case NorthHandle:
+                    c = ResizeTopCursor;
+                    break;
+                case NorthEastHandle:
+                    c = ResizeTopRightCursor;
+                    break;
+                default:
+                    c = NormalCursor;
+                    break;
+            }
+            [[renderer surface] setCursor:c];
+        }
+    }
 }
 
 - (void) mouseScrolledAt:(NSPoint)pos inDirection:(ScrollDirection)dir withMask:(InputMask)mask {
diff --git a/tikzit/src/gtk/Surface.h b/tikzit/src/gtk/Surface.h
index d2a0dba..449721f 100644
--- a/tikzit/src/gtk/Surface.h
+++ b/tikzit/src/gtk/Surface.h
@@ -19,6 +19,18 @@
 #import "RenderContext.h"
 #import "Transformer.h"
 
+typedef enum {
+    NormalCursor,
+    ResizeRightCursor,
+    ResizeBottomRightCursor,
+    ResizeBottomCursor,
+    ResizeBottomLeftCursor,
+    ResizeLeftCursor,
+    ResizeTopLeftCursor,
+    ResizeTopCursor,
+    ResizeTopRightCursor
+} Cursor;
+
 @protocol Surface;
 
 @protocol RenderDelegate
@@ -85,6 +97,8 @@
 - (void) zoomInAboutPoint:(NSPoint)p;
 - (void) zoomOutAboutPoint:(NSPoint)p;
 - (void) zoomResetAboutPoint:(NSPoint)p;
+
+- (void) setCursor:(Cursor)c;
 @end
 
 // vim:ft=objc:ts=8:et:sts=4:sw=4
diff --git a/tikzit/src/gtk/WidgetSurface.m b/tikzit/src/gtk/WidgetSurface.m
index 3538f72..14d799b 100644
--- a/tikzit/src/gtk/WidgetSurface.m
+++ b/tikzit/src/gtk/WidgetSurface.m
@@ -82,6 +82,14 @@ static gboolean scroll_event_cb (GtkWidget *widget, GdkEventScroll *event, Widge
     return self;
 }
 
+- (void) dealloc {
+    [[NSNotificationCenter defaultCenter] removeObserver:self];
+    [transformer release];
+    g_object_unref (G_OBJECT (widget));
+
+    [super dealloc];
+}
+
 - (void) invalidateRect:(NSRect)rect {
     if (!NSIsEmptyRect (rect)) {
         GdkWindow *window = gtk_widget_get_window (widget);
@@ -278,12 +286,40 @@ static gboolean scroll_event_cb (GtkWidget *widget, GdkEventScroll *event, Widge
     [self zoomTo:defaultScale aboutPoint:p];
 }
 
-- (void) dealloc {
-    [[NSNotificationCenter defaultCenter] removeObserver:self];
-    [transformer release];
-    g_object_unref (G_OBJECT (widget));
-
-    [super dealloc];
+- (void) setCursor:(Cursor)c {
+    GdkWindow *window = gtk_widget_get_window (widget);
+    GdkCursor *cursor = NULL;
+    switch (c) {
+        case ResizeRightCursor:
+            cursor = gdk_cursor_new (GDK_RIGHT_SIDE);
+            break;
+        case ResizeBottomRightCursor:
+            cursor = gdk_cursor_new (GDK_BOTTOM_RIGHT_CORNER);
+            break;
+        case ResizeBottomCursor:
+            cursor = gdk_cursor_new (GDK_BOTTOM_SIDE);
+            break;
+        case ResizeBottomLeftCursor:
+            cursor = gdk_cursor_new (GDK_BOTTOM_LEFT_CORNER);
+            break;
+        case ResizeLeftCursor:
+            cursor = gdk_cursor_new (GDK_LEFT_SIDE);
+            break;
+        case ResizeTopLeftCursor:
+            cursor = gdk_cursor_new (GDK_TOP_LEFT_CORNER);
+            break;
+        case ResizeTopCursor:
+            cursor = gdk_cursor_new (GDK_TOP_SIDE);
+            break;
+        case ResizeTopRightCursor:
+            cursor = gdk_cursor_new (GDK_TOP_RIGHT_CORNER);
+            break;
+        default: break;
+    }
+    gdk_window_set_cursor (window, cursor);
+    if (cursor != NULL) {
+        gdk_cursor_unref (cursor);
+    }
 }
 
 @end