Unscale coordinates coming back from backend via callback.

Now it seems to be complete.

3 files changed, 58 insertions, 0 deletions

diff --git a/navit/callback.c b/navit/callback.c
index c9ce5adea..edf594c3e 100644
--- a/navit/callback.c
+++ b/navit/callback.c
@@ -23,6 +23,7 @@
 #include "debug.h"
 #include "callback.h"
 
+
 struct callback {
     /* func has variable number of arguments, not (void),
      * but we must declare something... */
@@ -34,6 +35,8 @@ struct callback {
 };
 
 struct callback_list {
+    callback_patch patch;
+    void * patch_context;
     GList *list;
 };
 
@@ -115,6 +118,13 @@ void callback_list_remove_destroy(struct callback_list *l, struct callback *cb)
     g_free(cb);
 }
 
+void callback_list_add_patch_function (struct callback_list *l, callback_patch patch, void * context) {
+    if(!l)
+        return;
+    l->patch = patch;
+    l->patch_context = context;
+}
+
 void callback_call(struct callback *cb, int pcount, void **p) {
     int i;
     void *pf[8];
@@ -193,6 +203,8 @@ void callback_list_call_attr(struct callback_list *l, enum attr_type type, int p
     if (!l) {
         return;
     }
+    if(l->patch != NULL)
+        l->patch(l, type, pcount, p, l->patch_context);
 
     cbi=l->list;
     while (cbi) {
diff --git a/navit/callback.h b/navit/callback.h
index b0f4b9f81..c45735280 100644
--- a/navit/callback.h
+++ b/navit/callback.h
@@ -30,6 +30,7 @@ extern "C" {
 enum attr_type;
 struct callback;
 struct callback_list;
+typedef void (*callback_patch) (struct callback_list *l, enum attr_type type, int pcount, void **p, void * context);
 struct callback_list *callback_list_new(void);
 struct callback *callback_new_attr(void (*func)(void), enum attr_type type, int pcount, void **p);
 struct callback *callback_new_attr_args(void (*func)(void), enum attr_type type, int count, ...);
@@ -41,6 +42,7 @@ void callback_list_add(struct callback_list *l, struct callback *cb);
 struct callback *callback_list_add_new(struct callback_list *l, void (*func)(void), int pcount, void **p);
 void callback_list_remove(struct callback_list *l, struct callback *cb);
 void callback_list_remove_destroy(struct callback_list *l, struct callback *cb);
+void callback_list_add_patch_function (struct callback_list *l, callback_patch patch, void * context);
 void callback_call(struct callback *cb, int pcount, void **p);
 void callback_call_args(struct callback *cb, int count, ...);
 void callback_list_call_attr(struct callback_list *l, enum attr_type type, int pcount, void **p);
diff --git a/navit/graphics.c b/navit/graphics.c
index bfc5e93aa..96f4acb47 100644
--- a/navit/graphics.c
+++ b/navit/graphics.c
@@ -277,6 +277,49 @@ void graphics_set_rect(struct graphics *gra, struct point_rect *pr) {
 }
 
 /**
+ * @brief unscale coordinates coming from the graphics backend via callback.
+ *
+ * @param l pointer to callback list
+ * @param pcount number of parameters attached to this callback
+ * @param p list of parameters
+ * @param context context handed over by callback_list_add_patch_function, gra in this case.
+ * @return nothing
+ */
+static void graphics_dpi_patch (struct callback_list *l, enum attr_type type, int pcount, void **p, void * context) {
+    /* this is black magic. We scaled all coordinates to the graphics backend
+     * to compensate screen dpi. Since the backends communicate back via the callback
+     * list, we hook this function to unscale the coordinates coming back to
+     * navit before actually calling the callbacks.
+     */
+    struct graphics * gra;
+    gra = (struct graphics *) context;
+    if(gra == NULL)
+        return;
+
+    if((type == attr_resize) && (pcount >= 2)) {
+        int w, h;
+        w = GPOINTER_TO_INT(p[0]);
+        h = GPOINTER_TO_INT(p[1]);
+        dbg(lvl_debug,"scaling attr_resize %d, %d, %d", pcount, w, h);
+        p[0] = GINT_TO_POINTER(graphics_dpi_unscale(gra,w));
+        p[1] = GINT_TO_POINTER(graphics_dpi_unscale(gra,h));
+    }
+    if((type == attr_button) && (pcount >=3)) {
+        struct point * pnt;
+        pnt = (struct point *) p[2];
+        dbg(lvl_debug,"scaling attr_button %d, %d, %d", pcount, pnt->x, pnt->y);
+        *pnt = graphics_dpi_unscale_point(gra, pnt);
+    }
+    if((type == attr_motion) && (pcount >=1)) {
+        struct point * pnt;
+        pnt = (struct point *) p[0];
+        dbg(lvl_debug,"scaling attr_motion %d, %d, %d", pcount, pnt->x, pnt->y);
+        *pnt = graphics_dpi_unscale_point(gra, pnt);
+    }
+    /* any more?  attr_keypress doesn't come with coordinates */
+}
+
+/**
  * Creates a new graphics object
  * attr type required
  * @param <>
@@ -304,6 +347,7 @@ struct graphics * graphics_new(struct attr *parent, struct attr **attrs) {
     this_->cbl=callback_list_new();
     cbl_attr.type=attr_callback_list;
     cbl_attr.u.callback_list=this_->cbl;
+    callback_list_add_patch_function (this_->cbl, graphics_dpi_patch, (void*) this_);
     this_->attrs=attr_generic_add_attr(this_->attrs, &cbl_attr);
     this_->priv=(*graphicstype_new)(parent->u.navit, &this_->meth, this_->attrs, this_->cbl);
     this_->brightness=0;