3 files changed, 32 insertions, 8 deletions

diff --git a/apps/common/pdfapp.c b/apps/common/pdfapp.c
index ef342b43..70a83b29 100644
--- a/apps/common/pdfapp.c
+++ b/apps/common/pdfapp.c
@@ -512,7 +512,7 @@ void pdfapp_onkey(pdfapp_t *app, int c)
 	}
 }
 
-void pdfapp_onmouse(pdfapp_t *app, int x, int y, int btn, int state)
+void pdfapp_onmouse(pdfapp_t *app, int x, int y, int btn, int modifiers, int state)
 {
 	pdf_link *link;
 	fz_matrix ctm;
@@ -568,6 +568,30 @@ void pdfapp_onmouse(pdfapp_t *app, int x, int y, int btn, int state)
 			app->selr.y0 = y;
 			app->selr.y1 = y;
 		}
+		if (btn == 4 || btn == 5) /* scroll wheel */
+		{
+			int dir = btn == 4 ? 1 : -1;
+			app->ispanning = app->iscopying = 0;
+			if (modifiers & (1<<2))
+			{
+				/* zoom in/out if ctrl is pressed */
+				app->zoom += 0.1 * dir;
+				if (app->zoom > 3.0)
+					app->zoom = 3.0;
+				if (app->zoom < 0.1)
+					app->zoom = 0.1;
+				pdfapp_showpage(app, 0, 1);
+			}
+			else
+			{
+				/* scroll up/down, or left/right if
+				   shift is pressed */
+				int isx = (modifiers & (1<<0));
+				int xstep = isx ? 20 * dir : 0;
+				int ystep = !isx ? 20 * dir : 0;
+				pdfapp_panview(app, app->panx + xstep, app->pany + ystep);
+			}
+		}
 	}
 
 	else if (state == -1)
diff --git a/apps/unix/x11pdf.c b/apps/unix/x11pdf.c
index 0df360db..f12d27f1 100644
--- a/apps/unix/x11pdf.c
+++ b/apps/unix/x11pdf.c
@@ -379,7 +379,7 @@ void onkey(int c)
 	pdfapp_onkey(&gapp, c);
 }
 
-void onmouse(int x, int y, int btn, int state)
+void onmouse(int x, int y, int btn, int modifiers, int state)
 {
 	if (state != 0 && justcopied)
 	{
@@ -387,7 +387,7 @@ void onmouse(int x, int y, int btn, int state)
 		winrepaint(&gapp);
 	}
 
-	pdfapp_onmouse(&gapp, x, y, btn, state);
+	pdfapp_onmouse(&gapp, x, y, btn, modifiers, state);
 }
 
 void usage(void)
@@ -465,7 +465,7 @@ int main(int argc, char **argv)
 				len = XLookupString(&xevt.xkey, buf, sizeof buf, &keysym, 0);
 				if (len)
 					onkey(buf[0]);
-				onmouse(oldx, oldy, 0, 0);
+				onmouse(oldx, oldy, 0, 0, 0);
 
 				if (dirty)
 				{
@@ -478,16 +478,16 @@ int main(int argc, char **argv)
 			case MotionNotify:
 				oldx = xevt.xbutton.x;
 				oldy = xevt.xbutton.y;
-				onmouse(xevt.xbutton.x, xevt.xbutton.y, xevt.xbutton.button, 0);
+				onmouse(xevt.xbutton.x, xevt.xbutton.y, xevt.xbutton.button, xevt.xbutton.state, 0);
 				break;
 
 			case ButtonPress:
-				onmouse(xevt.xbutton.x, xevt.xbutton.y, xevt.xbutton.button, 1);
+				onmouse(xevt.xbutton.x, xevt.xbutton.y, xevt.xbutton.button, xevt.xbutton.state, 1);
 				break;
 
 			case ButtonRelease:
 				copytime = xevt.xbutton.time;
-				onmouse(xevt.xbutton.x, xevt.xbutton.y, xevt.xbutton.button, -1);
+				onmouse(xevt.xbutton.x, xevt.xbutton.y, xevt.xbutton.button, xevt.xbutton.state, -1);
 				break;
 
 			case SelectionRequest:
diff --git a/include/pdfapp.h b/include/pdfapp.h
index 407427e8..4792adda 100644
--- a/include/pdfapp.h
+++ b/include/pdfapp.h
@@ -69,7 +69,7 @@ void pdfapp_close(pdfapp_t *app);
 char *pdfapp_usage(pdfapp_t *app);
 
 void pdfapp_onkey(pdfapp_t *app, int c);
-void pdfapp_onmouse(pdfapp_t *app, int x, int y, int btn, int state);
+void pdfapp_onmouse(pdfapp_t *app, int x, int y, int btn, int modifiers, int state);
 void pdfapp_oncopy(pdfapp_t *app, unsigned short *ucsbuf, int ucslen);
 void pdfapp_onresize(pdfapp_t *app, int w, int h);