add horizontal wheel scroll support to w16 driver

1 files changed, 70 insertions, 50 deletions

diff --git a/mousew16.c b/mousew16.c
index d675001..f082a6d 100644
--- a/mousew16.c
+++ b/mousew16.c
@@ -35,7 +35,7 @@
 #define TRACE_EVENTS 0
 /** Verbosely trace scroll wheel code. */
 #define TRACE_WHEEL 0
-/** Number of lines to scroll per wheel event. */
+/** Number of lines to scroll per (vertical) wheel event. */
 #define WHEEL_SCROLL_LINES 2
 
 /** Windows 3.x only supports 1-2 mouse buttons anyway. */
@@ -117,7 +117,7 @@ static void print_window_name(HWND hWnd)
 #endif
 
 /** Helper function to traverse a window hierarchy and find a candidate scrollbar. */
-static BOOL CALLBACK __loadds find_scrollbar(HWND hWnd, LPARAM lParam)
+static BOOL CALLBACK __loadds find_scrollbar_enum_proc(HWND hWnd, LPARAM lParam)
 {
 	LPFINDSCROLLBARDATA data = (LPFINDSCROLLBARDATA) lParam;
 	char buffer[16];
@@ -149,6 +149,22 @@ static BOOL CALLBACK __loadds find_scrollbar(HWND hWnd, LPARAM lParam)
 	return ENUM_CHILD_WINDOW_CONTINUE;
 }
 
+/** Finds a scrollbar in the given window. */
+static HWND find_scrollbar(HWND hWnd, BOOL vertical)
+{
+	FINDSCROLLBARDATA data;
+	data.vertical = vertical;
+	data.scrollbar = 0;
+
+#if TRACE_WHEEL
+	dprintf(DPREFIX "find scrollbar on hWnd=0x%x...\n", hWnd);
+#endif
+
+	userapi.EnumChildWindows(hWnd, find_scrollbar_enum_proc, (LONG) (LPVOID) &data);
+
+	return data.scrollbar;
+}
+
 /** Send scrolling messages to given window.
  *  @param hWnd window to scroll.
  *  @param vertical true if vertical, false if horizontal.
@@ -160,7 +176,9 @@ static void post_scroll_msg(HWND hWnd, BOOL vertical, int z, HWND hScrollBar)
 	UINT msg = vertical ? WM_VSCROLL : WM_HSCROLL;
 	WPARAM wParam = z < 0 ? SB_LINEUP : SB_LINEDOWN;
 	LPARAM lParam = MAKELPARAM(0, hScrollBar);
-	UINT i, lines = (z < 0 ? -z : z) * WHEEL_SCROLL_LINES;
+	UINT i, lines = (z < 0 ? -z : z);
+
+	if (!vertical) lines *= WHEEL_SCROLL_LINES;
 
 #if TRACE_WHEEL
 	dprintf(DPREFIX "sending scroll msg to hWnd=0x%x from=0x%x vert=%d lines=%u\n", hWnd, hScrollBar, vertical, lines);
@@ -173,7 +191,7 @@ static void post_scroll_msg(HWND hWnd, BOOL vertical, int z, HWND hScrollBar)
 }
 
 /** Send wheel scrolling events to the most likely candidate window. */
-static void send_wheel_movement(int8_t z)
+static void send_wheel_movement(int8_t z, BOOL vertical)
 {
 	POINT point;
 	HWND hWnd;
@@ -202,54 +220,55 @@ static void send_wheel_movement(int8_t z)
 		dprintf(DPREFIX "hWnd=0x%x style=0x%lx\n", hWnd, style);
 #endif
 
-		if (style & WS_VSCROLL) {
-#if TRACE_WHEEL
-			dprintf(DPREFIX "found WS_VSCROLL\n");
-#endif
-			post_scroll_msg(hWnd, TRUE, z, 0);
-			break;
-		} else if (style & WS_HSCROLL) {
-#if TRACE_WHEEL
-			dprintf(DPREFIX "found WS_HSCROLL\n");
-#endif
-			post_scroll_msg(hWnd, FALSE, z, 0);
-			break;
-		} else {
-			FINDSCROLLBARDATA data;
-
-			// Let's check if we can find a vertical scroll bar in this window..
-#if TRACE_WHEEL
-			dprintf(DPREFIX "find vertical scrollbar...\n");
-#endif
-			data.vertical = TRUE;
-			data.scrollbar = 0;
-			userapi.EnumChildWindows(hWnd, find_scrollbar, (LONG) (LPVOID) &data);
-			if (data.scrollbar) {
-				post_scroll_msg(hWnd, TRUE, z, data.scrollbar);
+		if (vertical) {
+			// Check if this window is scrollable...
+			if (style & WS_VSCROLL) {
+				post_scroll_msg(hWnd, TRUE, z, 0);
 				break;
-			}
-
-			// Try a horizontal scrollbar now
-#if TRACE_WHEEL
-			dprintf(DPREFIX "find horizontal scrollbar...\n");
-#endif
-			data.vertical = FALSE;
-			data.scrollbar = 0;
-			userapi.EnumChildWindows(hWnd, find_scrollbar, (LONG) (LPVOID) &data);
-			if (data.scrollbar) {
-				post_scroll_msg(hWnd, FALSE, z, data.scrollbar);
+			} else if (style & WS_HSCROLL) {
+				post_scroll_msg(hWnd, FALSE, z, 0);
 				break;
-			}
-
-			// Otherwise, try again on the parent window
-			if (style & WS_CHILD) {
-#if TRACE_WHEEL
-				dprintf(DPREFIX "go into parent...\n");
-#endif
-				hWnd = userapi.GetParent(hWnd);
 			} else {
-				// This was already a topmost window
+				// Otherwise, let's see if we can find a vertical scroll bar in this window..
+				HWND scrollbar = find_scrollbar(hWnd, TRUE);
+				if (scrollbar) {
+					post_scroll_msg(hWnd, TRUE, z, scrollbar);
+					break;
+				}
+
+				// Try a horizontal scrollbar second
+				scrollbar = find_scrollbar(hWnd, FALSE);
+				if (scrollbar) {
+					post_scroll_msg(hWnd, FALSE, z, scrollbar);
+					break;
+				}
+
+				// Otherwise, continue search on the parent window
+				if (style & WS_CHILD) {
+					hWnd = userapi.GetParent(hWnd);
+				} else {
+					// This was already a topmost window
+					break;
+				}
+			}
+		} else {
+			// Similar to above except we try only horizontal scrollbars
+			if (style & WS_HSCROLL) {
+				post_scroll_msg(hWnd, FALSE, z, 0);
 				break;
+			} else {
+				HWND scrollbar = find_scrollbar(hWnd, FALSE);
+				if (scrollbar) {
+					post_scroll_msg(hWnd, FALSE, z, scrollbar);
+					break;
+				}
+
+				if (style & WS_CHILD) {
+					hWnd = userapi.GetParent(hWnd);
+				} else {
+					// This was already a topmost window
+					break;
+				}
 			}
 		}
 	}
@@ -281,11 +300,12 @@ static void FAR int33_mouse_callback(uint16_t events, uint16_t buttons, int16_t
 	}
 
 #if USE_WHEEL
-	if (flags.wheel && (events & INT33_EVENT_MASK_WHEEL_MOVEMENT)) {
+	if (flags.wheel && (events & INT33_EVENT_MASK_WHEEL_MOVEMENT|INT33_EVENT_MASK_HORIZ_WHEEL_MOVEMENT)) {
 		// If wheel API is enabled, higher byte of buttons contains wheel movement
 		int8_t z = (buttons & 0xFF00) >> 8;
+		BOOL vertical = !(events & INT33_EVENT_MASK_HORIZ_WHEEL_MOVEMENT);
 		if (z) {
-			send_wheel_movement(z);
+			send_wheel_movement(z, vertical);
 		}
 	}
 #endif