Mouse becoming "unstuck" when resizing windows fixed.

dvx/dvxApp.c

@@ -794,7 +794,15 @@ static void dispatchEvents(AppContextT *ctx) {
     // Handle active resize
     if (ctx->stack.resizeWindow >= 0) {
         if (buttons & MOUSE_LEFT) {
-            wmResizeMove(&ctx->stack, &ctx->dirty, &ctx->display, mx, my);
+            int32_t clampX = mx;
+            int32_t clampY = my;
+            wmResizeMove(&ctx->stack, &ctx->dirty, &ctx->display, &clampX, &clampY);
+
+            if (clampX != mx || clampY != my) {
+                platformMouseWarp(clampX, clampY);
+                ctx->mouseX = clampX;
+                ctx->mouseY = clampY;
+            }
         } else {
             wmResizeEnd(&ctx->stack);
         }

dvx/dvxWidget.h

@@ -899,6 +899,10 @@ void wgtSetEnabled(WidgetT *w, bool enabled);
 // Set read-only mode (allows scrolling/selection but blocks editing)
 void wgtSetReadOnly(WidgetT *w, bool readOnly);
 
+// Set/get keyboard focus
+void wgtSetFocused(WidgetT *w);
+WidgetT *wgtGetFocused(void);
+
 // Show/hide a widget
 void wgtSetVisible(WidgetT *w, bool visible);
 

dvx/dvxWm.c

@@ -2011,14 +2011,16 @@ void wmResizeEnd(WindowStackT *stack) {
 // which would be confusing — the user's manual resize represents their
 // new intent.
 
-void wmResizeMove(WindowStackT *stack, DirtyListT *dl, const DisplayT *d, int32_t mouseX, int32_t mouseY) {
+void wmResizeMove(WindowStackT *stack, DirtyListT *dl, const DisplayT *d, int32_t *mouseX, int32_t *mouseY) {
     if (stack->resizeWindow < 0 || stack->resizeWindow >= stack->count) {
         return;
     }
 
     WindowT *win = stack->windows[stack->resizeWindow];
-    int32_t  dx  = mouseX - stack->dragOffX;
-    int32_t  dy  = mouseY - stack->dragOffY;
+    int32_t  mx  = *mouseX;
+    int32_t  my  = *mouseY;
+    int32_t  dx  = mx - stack->dragOffX;
+    int32_t  dy  = my - stack->dragOffY;
 
     // Compute dynamic minimum size for this window
     int32_t minW;
@@ -2032,13 +2034,6 @@ void wmResizeMove(WindowStackT *stack, DirtyListT *dl, const DisplayT *d, int32_
     // Mark old position dirty
     dirtyListAdd(dl, win->x, win->y, win->w, win->h);
 
-    // Track whether each axis actually changed, so we only update
-    // dragOff on axes where the resize was applied. If clamped, leaving
-    // dragOff unchanged makes the border "stick" to the mouse when the
-    // user reverses direction, instead of creating a dead zone.
-    bool appliedX = false;
-    bool appliedY = false;
-
     if (stack->resizeEdge & RESIZE_LEFT) {
         int32_t newX = win->x + dx;
         int32_t newW = win->w - dx;
@@ -2053,11 +2048,14 @@ void wmResizeMove(WindowStackT *stack, DirtyListT *dl, const DisplayT *d, int32_
             newX  = 0;
         }
 
-        if (newW >= minW) {
+        if (newW < minW) {
+            newW = minW;
+            newX = win->x + win->w - minW;
+        }
+
         win->x = newX;
         win->w = newW;
-            appliedX = true;
-        }
+        mx     = newX;
     }
 
     if (stack->resizeEdge & RESIZE_RIGHT) {
@@ -2071,10 +2069,12 @@ void wmResizeMove(WindowStackT *stack, DirtyListT *dl, const DisplayT *d, int32_
             newW = d->width - win->x;
         }
 
-        if (newW >= minW) {
-            win->w   = newW;
-            appliedX = true;
+        if (newW < minW) {
+            newW = minW;
         }
+
+        win->w = newW;
+        mx     = win->x + newW;
     }
 
     if (stack->resizeEdge & RESIZE_TOP) {
@@ -2091,11 +2091,14 @@ void wmResizeMove(WindowStackT *stack, DirtyListT *dl, const DisplayT *d, int32_
             newY  = 0;
         }
 
-        if (newH >= minH) {
+        if (newH < minH) {
+            newH = minH;
+            newY = win->y + win->h - minH;
+        }
+
         win->y = newY;
         win->h = newH;
-            appliedY = true;
-        }
+        my     = newY;
     }
 
     if (stack->resizeEdge & RESIZE_BOTTOM) {
@@ -2109,10 +2112,12 @@ void wmResizeMove(WindowStackT *stack, DirtyListT *dl, const DisplayT *d, int32_
             newH = d->height - win->y;
         }
 
-        if (newH >= minH) {
-            win->h   = newH;
-            appliedY = true;
+        if (newH < minH) {
+            newH = minH;
         }
+
+        win->h = newH;
+        my     = win->y + newH;
     }
 
     // If resized while maximized, consider it no longer maximized
@@ -2134,13 +2139,14 @@ void wmResizeMove(WindowStackT *stack, DirtyListT *dl, const DisplayT *d, int32_
         win->contentDirty = true;
     }
 
-    if (appliedX) {
-        stack->dragOffX = mouseX;
-    }
+    // Always update dragOff to the clamped position so the next delta
+    // is computed from the edge, not from where the mouse wandered.
+    stack->dragOffX = mx;
+    stack->dragOffY = my;
 
-    if (appliedY) {
-        stack->dragOffY = mouseY;
-    }
+    // Report clamped position back so the caller can warp the cursor
+    *mouseX = mx;
+    *mouseY = my;
 
     // Mark new position dirty
     dirtyListAdd(dl, win->x, win->y, win->w, win->h);

dvx/dvxWm.h

@@ -136,7 +136,9 @@ void wmDragMove(WindowStackT *stack, DirtyListT *dl, int32_t mouseX, int32_t mou
 // Update window dimensions during an active resize. Enforces MIN_WINDOW_W/H
 // and optional maxW/maxH constraints. Reallocates the content buffer if the
 // content area size changed, then calls onResize to notify the application.
-void wmResizeMove(WindowStackT *stack, DirtyListT *dl, const DisplayT *d, int32_t mouseX, int32_t mouseY);
+// mouseX/mouseY are in/out: on return they hold the clamped position so the
+// caller can warp the hardware cursor to keep it stuck to the window edge.
+void wmResizeMove(WindowStackT *stack, DirtyListT *dl, const DisplayT *d, int32_t *mouseX, int32_t *mouseY);
 
 // Begin a window drag operation. Records the mouse offset from the window
 // origin so the window doesn't jump to the cursor position.

dvx/platform/dvxPlatform.h

@@ -139,6 +139,11 @@ bool platformMouseWheelInit(void);
 // driver between polls).
 int32_t platformMouseWheelPoll(void);
 
+// Move the mouse cursor to an absolute screen position. Uses INT 33h
+// function 04h on DOS, SDL_WarpMouseInWindow on Linux. Used to clamp
+// the cursor to window edges during resize operations.
+void platformMouseWarp(int32_t x, int32_t y);
+
 // ============================================================
 // Input — Keyboard
 // ============================================================

dvx/platform/dvxPlatformDos.c

@@ -1199,6 +1199,25 @@ int32_t platformMouseWheelPoll(void) {
 }
 
 
+// ============================================================
+// platformMouseWarp
+// ============================================================
+//
+// Moves the mouse cursor to an absolute screen position via INT 33h
+// function 04h. Used to clamp the cursor to window edges during resize
+// so the pointer visually sticks to the border.
+
+void platformMouseWarp(int32_t x, int32_t y) {
+    __dpmi_regs r;
+
+    memset(&r, 0, sizeof(r));
+    r.x.ax = 0x0004;
+    r.x.cx = x;
+    r.x.dx = y;
+    __dpmi_int(0x33, &r);
+}
+
+
 // ============================================================
 // platformSpanCopy8
 // ============================================================

dvx/widgets/widgetOps.c

@@ -454,6 +454,15 @@ void wgtSetDebugLayout(AppContextT *ctx, bool enabled) {
 }
 
 
+// ============================================================
+// wgtGetFocused
+// ============================================================
+
+WidgetT *wgtGetFocused(void) {
+    return sFocusedWidget;
+}
+
+
 // ============================================================
 // wgtSetEnabled
 // ============================================================
@@ -466,6 +475,26 @@ void wgtSetEnabled(WidgetT *w, bool enabled) {
 }
 
 
+// ============================================================
+// wgtSetFocused
+// ============================================================
+
+void wgtSetFocused(WidgetT *w) {
+    if (!w || !w->enabled) {
+        return;
+    }
+
+    if (sFocusedWidget && sFocusedWidget != w) {
+        sFocusedWidget->focused = false;
+        wgtInvalidatePaint(sFocusedWidget);
+    }
+
+    w->focused     = true;
+    sFocusedWidget = w;
+    wgtInvalidatePaint(w);
+}
+
+
 // ============================================================
 // wgtSetReadOnly
 // ============================================================

dvxshell/shellExport.c

@@ -352,7 +352,9 @@ DXE_EXPORT_TABLE(shellExportTable)
     DXE_EXPORT(wgtSetText)
     DXE_EXPORT(wgtSetTooltip)
     DXE_EXPORT(wgtGetText)
+    DXE_EXPORT(wgtGetFocused)
     DXE_EXPORT(wgtSetEnabled)
+    DXE_EXPORT(wgtSetFocused)
     DXE_EXPORT(wgtSetReadOnly)
     DXE_EXPORT(wgtSetVisible)
     DXE_EXPORT(wgtGetContext)