better Input Method Editor (IME) support

Features:

- Allow input methods swap with hotkey (E.g. left ctrl + left shift).
- Over-the-spot pre-editing style, pre-edit data placed over insertion point.
- Restart IME without segmentation fault.

TODO:

- Automatically pickup IME if st started before IME

1 files changed, 52 insertions, 17 deletions

diff --git a/x.c b/x.c
index 0422421..865dacc 100644
--- a/x.c
+++ b/x.c
@@ -139,6 +139,9 @@ static void xdrawglyphfontspecs(const XftGlyphFontSpec *, Glyph, int, int, int);
 static void xdrawglyph(Glyph, int, int);
 static void xclear(int, int, int, int);
 static int xgeommasktogravity(int);
+static void ximopen(Display *);
+static void ximinstantiate(Display *, XPointer, XPointer);
+static void ximdestroy(XIM, XPointer, XPointer);
 static void xinit(int, int);
 static void cresize(int, int);
 static void xresize(int, int);
@@ -997,6 +1000,43 @@ xunloadfonts(void)
 }
 
 void
+ximopen(Display *dpy)
+{
+        XIMCallback destroy = { .client_data = NULL, .callback = ximdestroy };
+
+        if ((xw.xim = XOpenIM(xw.dpy, NULL, NULL, NULL)) == NULL) {
+                XSetLocaleModifiers("@im=local");
+                if ((xw.xim = XOpenIM(xw.dpy, NULL, NULL, NULL)) == NULL) {
+                        XSetLocaleModifiers("@im=");
+                        if ((xw.xim = XOpenIM(xw.dpy, NULL, NULL, NULL)) == NULL)
+                                die("XOpenIM failed. Could not open input device.\n");
+                }
+        }
+        if (XSetIMValues(xw.xim, XNDestroyCallback, &destroy, NULL) != NULL)
+                die("XSetIMValues failed. Could not set input method value.\n");
+        xw.xic = XCreateIC(xw.xim, XNInputStyle, XIMPreeditNothing | XIMStatusNothing,
+                                XNClientWindow, xw.win, XNFocusWindow, xw.win, NULL);
+        if (xw.xic == NULL)
+                die("XCreateIC failed. Could not obtain input method.\n");
+}
+
+void
+ximinstantiate(Display *dpy, XPointer client, XPointer call)
+{
+        ximopen(dpy);
+        XUnregisterIMInstantiateCallback(xw.dpy, NULL, NULL, NULL,
+                                        ximinstantiate, NULL);
+}
+
+void
+ximdestroy(XIM xim, XPointer client, XPointer call)
+{
+        xw.xim = NULL;
+        XRegisterIMInstantiateCallback(xw.dpy, NULL, NULL, NULL,
+                                        ximinstantiate, NULL);
+}
+
+void
 xinit(int cols, int rows)
 {
         XGCValues gcvalues;
@@ -1033,7 +1073,7 @@ xinit(int cols, int rows)
         xw.attrs.background_pixel = dc.col[defaultbg].pixel;
         xw.attrs.border_pixel = dc.col[defaultbg].pixel;
         xw.attrs.bit_gravity = NorthWestGravity;
-        xw.attrs.event_mask = FocusChangeMask | KeyPressMask
+        xw.attrs.event_mask = FocusChangeMask | KeyPressMask | KeyReleaseMask
                 | ExposureMask | VisibilityChangeMask | StructureNotifyMask
                 | ButtonMotionMask | ButtonPressMask | ButtonReleaseMask;
         xw.attrs.colormap = xw.cmap;
@@ -1061,22 +1101,7 @@ xinit(int cols, int rows)
         xw.draw = XftDrawCreate(xw.dpy, xw.buf, xw.vis, xw.cmap);
 
         /* input methods */
-        if ((xw.xim = XOpenIM(xw.dpy, NULL, NULL, NULL)) == NULL) {
-                XSetLocaleModifiers("@im=local");
-                if ((xw.xim =  XOpenIM(xw.dpy, NULL, NULL, NULL)) == NULL) {
-                        XSetLocaleModifiers("@im=");
-                        if ((xw.xim = XOpenIM(xw.dpy,
-                                        NULL, NULL, NULL)) == NULL) {
-                                die("XOpenIM failed. Could not open input"
-                                        " device.\n");
-                        }
-                }
-        }
-        xw.xic = XCreateIC(xw.xim, XNInputStyle, XIMPreeditNothing
-                                           | XIMStatusNothing, XNClientWindow, xw.win,
-                                           XNFocusWindow, xw.win, NULL);
-        if (xw.xic == NULL)
-                die("XCreateIC failed. Could not obtain input method.\n");
+        ximopen(xw.dpy);
 
         /* white cursor, black outline */
         cursor = XCreateFontCursor(xw.dpy, mouseshape);
@@ -1555,6 +1580,16 @@ xfinishdraw(void)
 }
 
 void
+xximspot(int x, int y)
+{
+        XPoint spot = { borderpx + x * win.cw, borderpx + (y + 1) * win.ch };
+        XVaNestedList attr = XVaCreateNestedList(0, XNSpotLocation, &spot, NULL);
+
+        XSetICValues(xw.xic, XNPreeditAttributes, attr, NULL);
+        XFree(attr);
+}
+
+void
 expose(XEvent *ev)
 {
         redraw();