UI: Select regions of text and toggle its stylesoc-2022-text-usability

1. Text can be selected along the mouse pointer by dragging the cursor .
2. After the selection we can toggle the style of the selected region.
3. Word can be selected using double click.

4 files changed, 151 insertions, 50 deletions

diff --git a/release/scripts/startup/bl_ui/properties_data_curve.py b/release/scripts/startup/bl_ui/properties_data_curve.py
index e986afd2f3d..bc8d07e8b13 100644
--- a/release/scripts/startup/bl_ui/properties_data_curve.py
+++ b/release/scripts/startup/bl_ui/properties_data_curve.py
@@ -364,10 +364,11 @@ class DATA_PT_font(CurveButtonsPanelText, Panel):
                 row.prop(char, "use_underline", toggle=True)
                 row.prop(char, "use_small_caps", toggle=True)
             else:
-                layout.operator("font.style_toggle", text="Bold", icon='BOLD' , depress = text.select_is_bold).style = 'BOLD'
-                layout.operator("font.style_toggle", text="Italic", icon='ITALIC' , depress = text.select_is_italics).style = 'ITALIC'
-                layout.operator("font.style_toggle", text="Underline", icon='UNDERLINE' , depress = text.select_is_underline).style = 'UNDERLINE'
-                layout.operator("font.style_toggle", text="Small Caps", icon='SMALL_CAPS' , depress = text.select_is_smallcaps).style = 'SMALL_CAPS'
+                row = layout.row(align=True)
+                row.operator("font.style_toggle", text="Bold", icon='BOLD' , depress = text.select_is_bold).style = 'BOLD'
+                row.operator("font.style_toggle", text="Italic", icon='ITALIC' , depress = text.select_is_italics).style = 'ITALIC'
+                row.operator("font.style_toggle", text="Underline", icon='UNDERLINE' , depress = text.select_is_underline).style = 'UNDERLINE'
+                row.operator("font.style_toggle", text="Small Caps", icon='SMALL_CAPS' , depress = text.select_is_smallcaps).style = 'SMALL_CAPS'
 
 
 class DATA_PT_font_transform(CurveButtonsPanelText, Panel):
diff --git a/source/blender/blenkernel/BKE_vfont.h b/source/blender/blenkernel/BKE_vfont.h
index 4cb3a595140..1b2166411a6 100644
--- a/source/blender/blenkernel/BKE_vfont.h
+++ b/source/blender/blenkernel/BKE_vfont.h
@@ -82,6 +82,19 @@ bool BKE_vfont_to_curve_ex(struct Object *ob,
                            bool *r_text_free,
                            struct CharTrans **r_chartransdata);
 bool BKE_vfont_to_curve_nubase(struct Object *ob, int mode, struct ListBase *r_nubase);
+
+bool BKE_vfont_to_curve_ex2(struct Object *ob,
+                           struct Curve *cu,
+                           int mode,
+                           struct ListBase *r_nubase,
+                           const char32_t **r_text,
+                           int *r_text_len,
+                           bool *r_text_free,
+                           struct CharTrans **r_chartransdata,
+                           float cursor_location[2], int *r_cursor_locaiton_pos);
+
+bool BKE_vfont_to_curve_curloc(struct Object *ob, int mode,float cursor_location[2], int *r_cursor_locaiton_pos);                           
+
 /**
  * \warning Expects to have access to evaluated data (i.e. passed object should be evaluated one).
  */
diff --git a/source/blender/blenkernel/intern/vfont.c b/source/blender/blenkernel/intern/vfont.c
index b1fd3d3c0e8..ec80a53dca7 100644
--- a/source/blender/blenkernel/intern/vfont.c
+++ b/source/blender/blenkernel/intern/vfont.c
@@ -765,7 +765,7 @@ static float vfont_descent(const VFontData *vfd)
   return vfd->em_height - vfont_ascent(vfd);
 }
 
-static bool vfont_to_curve(Object *ob,
+static bool vfont_to_curve_ex(Object *ob,
                            Curve *cu,
                            int mode,
                            VFontToCurveIter *iter_data,
@@ -773,7 +773,8 @@ static bool vfont_to_curve(Object *ob,
                            const char32_t **r_text,
                            int *r_text_len,
                            bool *r_text_free,
-                           struct CharTrans **r_chartransdata)
+                           struct CharTrans **r_chartransdata,
+                           float cursor_location[2], int *r_cursor_locaiton_pos)
 {
   EditFont *ef = cu->editfont;
   EditFontSelBox *selboxes = NULL;
@@ -826,6 +827,14 @@ static bool vfont_to_curve(Object *ob,
     return ok;
   }
 
+  if(cursor_location==NULL)
+  {  
+    float cur_loc_temp[2];
+    cur_loc_temp[0]=0.0;
+    cur_loc_temp[1]=0.0;
+    cursor_location=cur_loc_temp;
+  } 
+
   vfd = vfont_get_data(vfont);
 
   /* The VFont Data can not be found */
@@ -908,8 +917,13 @@ static bool vfont_to_curve(Object *ob,
   }
 
   i = 0;
-  int ret=0;
-  float min_dist=0.0f;
+  int ret=-1;
+  float min_dist;
+  if(ef!=NULL && ob!=NULL)
+  { float ffx=cursor_location[0];
+    float ffy=cursor_location[1]; 
+    min_dist=ffx*ffx+ffy*ffy;
+  }
   while (i <= slen) {
     /* Characters in the list */
     info = &custrinfo[i];
@@ -1125,33 +1139,39 @@ static bool vfont_to_curve(Object *ob,
     }
     ct++;
     if (ef != NULL && ob != NULL){
-      float fx=ef->m_loc[0];
-      float fy=ef->m_loc[1];
+      float fx=cursor_location[0];
+      float fy=cursor_location[1];
       float di= (fx-xof)*(fx-xof)+(fy-yof)*(fy-yof);
-      if(i==0)
+      float di2=fx*fx+fy*fy;
+
+      if(di2<=min_dist && di2<di)
       {
-        min_dist=di;
-        ret=i;
+        min_dist=di2;
+        ret=-1;
       }
-      if(di<min_dist)
+      else if(di<min_dist)
       {
         min_dist=di;
         ret=i;
       } 
+
     }
     i++;
   }
   if (ef != NULL && ob != NULL)
   {
-    if(ret==0)
+
+    if(ret==-1)
     {
       ret++;
-      ef->m_pos=ret;
+      if(r_cursor_locaiton_pos)
+        *r_cursor_locaiton_pos=ret;
     }
-    else if(ret>0 && ret<=ef->len-1)
+    else if(ret>=0 && ret<=ef->len-1)
     {
       ret++;
-      ef->m_pos=ret;
+      if(r_cursor_locaiton_pos)
+        *r_cursor_locaiton_pos=ret;
     }
   }
   current_line_length += xof + twidth - MARGIN_X_MIN;
@@ -1754,6 +1774,20 @@ finally:
 #undef MARGIN_Y_MIN
 }
 
+
+static bool vfont_to_curve(Object *ob,
+                           Curve *cu,
+                           int mode,
+                           VFontToCurveIter *iter_data,
+                           ListBase *r_nubase,
+                           const char32_t **r_text,
+                           int *r_text_len,
+                           bool *r_text_free,
+                           struct CharTrans **r_chartransdata)
+{
+  return vfont_to_curve_ex(ob,cu,mode,iter_data,r_nubase,r_text,r_text_len,r_text_free,r_chartransdata,NULL,NULL);
+
+}
 #undef DESCENT
 #undef ASCENT
 
@@ -1775,8 +1809,34 @@ bool BKE_vfont_to_curve_ex(Object *ob,
   };
 
   do {
-    data.ok &= vfont_to_curve(
-        ob, cu, mode, &data, r_nubase, r_text, r_text_len, r_text_free, r_chartransdata);
+    data.ok &= vfont_to_curve_ex(
+        ob, cu, mode, &data, r_nubase, r_text, r_text_len, r_text_free, r_chartransdata,NULL,NULL);
+  } while (data.ok && ELEM(data.status, VFONT_TO_CURVE_SCALE_ONCE, VFONT_TO_CURVE_BISECT));
+
+  return data.ok;
+}
+
+bool BKE_vfont_to_curve_ex2(Object *ob,
+                           Curve *cu,
+                           int mode,
+                           ListBase *r_nubase,
+                           const char32_t **r_text,
+                           int *r_text_len,
+                           bool *r_text_free,
+                           struct CharTrans **r_chartransdata,
+                           float cursor_location[2], int *r_cursor_locaiton_pos)
+{
+  VFontToCurveIter data = {
+      .iteraction = cu->totbox * FONT_TO_CURVE_SCALE_ITERATIONS,
+      .scale_to_fit = 1.0f,
+      .word_wrap = true,
+      .ok = true,
+      .status = VFONT_TO_CURVE_INIT,
+  };
+
+  do {
+    data.ok &= vfont_to_curve_ex(
+        ob, cu, mode, &data, r_nubase, r_text, r_text_len, r_text_free, r_chartransdata,cursor_location,r_cursor_locaiton_pos);
   } while (data.ok && ELEM(data.status, VFONT_TO_CURVE_SCALE_ONCE, VFONT_TO_CURVE_BISECT));
 
   return data.ok;
@@ -1799,6 +1859,13 @@ bool BKE_vfont_to_curve(Object *ob, int mode)
   return BKE_vfont_to_curve_ex(ob, ob->data, mode, &cu->nurb, NULL, NULL, NULL, NULL);
 }
 
+bool BKE_vfont_to_curve_curloc(Object *ob, int mode,float cursor_location[2], int *r_cursor_locaiton_pos)
+{
+  Curve *cu = ob->data;
+
+  return BKE_vfont_to_curve_ex2(ob,ob->data,mode,&cu->nurb,NULL,NULL,NULL,NULL,cursor_location,r_cursor_locaiton_pos);
+}
+
 /* -------------------------------------------------------------------- */
 /** \name VFont Clipboard
  * \{ */
diff --git a/source/blender/editors/curve/editfont.c b/source/blender/editors/curve/editfont.c
index c45c6887279..5dbebf1fa0e 100644
--- a/source/blender/editors/curve/editfont.c
+++ b/source/blender/editors/curve/editfont.c
@@ -423,6 +423,29 @@ static void text_update_edited(bContext *C, Object *obedit, int mode)
   WM_event_add_notifier(C, NC_GEOM | ND_DATA, obedit->data);
 }
 
+static void text_update_edited_ex(bContext *C, Object *obedit, int mode,float cursor_location[2], int *r_cursor_locaiton_pos)
+{
+  Curve *cu = obedit->data;
+  EditFont *ef = cu->editfont;
+
+  BLI_assert(ef->len >= 0);
+    Depsgraph *depsgraph = CTX_data_ensure_evaluated_depsgraph(C);
+    BKE_vfont_to_curve_curloc(DEG_get_evaluated_object(depsgraph, obedit), mode,cursor_location,r_cursor_locaiton_pos);
+
+  cu->curinfo = ef->textbufinfo[ef->pos ? ef->pos - 1 : 0];
+
+  if (obedit->totcol > 0) {
+    obedit->actcol = cu->curinfo.mat_nr;
+    if (obedit->actcol < 1) {
+      obedit->actcol = 1;
+    }
+  }
+
+  DEG_id_tag_update(obedit->data, ID_RECALC_SELECT);
+  WM_event_add_notifier(C, NC_GEOM | ND_DATA, obedit->data);
+}
+
+
 static int kill_selection(Object *obedit, int ins) /* ins == new character len */
 {
   Curve *cu = obedit->data;
@@ -1759,33 +1782,39 @@ void FONT_OT_text_insert(wmOperatorType *ot)
 /* -------------------------------------------------------------------- */
 /** \name Font Select Operator
  * \{ */
-static void font_cursor_set_apply(bContext *C, wmOperator *op, const wmEvent *event)
+static void font_cursor_set_apply(bContext *C, const wmEvent *event)
 {
   Object *obedit = CTX_data_active_object(C);
   Curve *cu = obedit->data;
   EditFont *ef = cu->editfont;
   ARegion *region = CTX_wm_region(C);
+  int cur_loc_pos;
   float rout[3];
   float mal[2];
   mal[0]=event->mval[0];
   mal[1]=event->mval[1];
   const float *co = obedit->obmat[3];
-  const float *no = obedit->obmat[2]; /* Z axis. */
+  const float *no = obedit->obmat[2];
   float plane[4];
   plane_from_point_normal_v3(plane, co, no);
   ED_view3d_win_to_3d_on_plane(region,plane,mal,true,rout);
   mul_m4_v3(obedit->imat, rout);
-  ef->m_loc[0]=rout[0];
-  ef->m_loc[1]=rout[1];
-  ef->pos=ef->m_pos;
-    if ((select) && (ef->selstart==0)) {
-      if(ef->pos==0)
-      ef->selstart = ef->selend =1;
-      else
-      ef->selstart = ef->selend = ef->pos+1;
+  float curs_loc[2];
+  curs_loc[0]=rout[0];
+  curs_loc[1]=rout[1];
+
+  text_update_edited_ex(C, obedit, FO_CURS,curs_loc,&cur_loc_pos);
+  if(cur_loc_pos<=ef->len)
+  {  
+      if ((!ef->is_selected) && (ef->selstart==0)) {
+        if(ef->pos==0)
+        ef->selstart = ef->selend =1;
+        else
+        ef->selstart = ef->selend = cur_loc_pos+1;
+    }
+    ef->selend=cur_loc_pos;
+    ef->pos=cur_loc_pos;
   }
-  ef->selend=ef->pos;
-  text_update_edited(C, obedit, true);
 
 }
 
@@ -1795,32 +1824,26 @@ static int font_selection_set_invoke(bContext *C, wmOperator *op, const wmEvent
   Curve *cu = obedit->data;
   EditFont *ef = cu->editfont;
 
-  WM_event_add_modal_handler(C, op);
-
-  font_cursor_set_apply(C, op, event);
+  font_cursor_set_apply(C, event);
   ef->selstart=0;
   ef->selend=0;
-  
-  text_update_edited(C, obedit, true);
+  WM_event_add_modal_handler(C, op);
 
   return OPERATOR_RUNNING_MODAL; 
 }
 
-static int font_selection_set_modal(bContext *C, wmOperator *op, const wmEvent *event)
+static int font_selection_set_modal(bContext *C, wmOperator *UNUSED(op), const wmEvent *event)
 {
-  Object *obedit = CTX_data_active_object(C);
-  Curve *cu = obedit->data;
-  EditFont *ef = cu->editfont;
+
   switch (event->type) {
     case LEFTMOUSE:
-      font_cursor_set_apply(C, op, event);
+      font_cursor_set_apply(C, event);
       return OPERATOR_FINISHED;
     case MIDDLEMOUSE:
     case RIGHTMOUSE:
       return OPERATOR_FINISHED; 
-    case TIMER:
     case MOUSEMOVE:
-      font_cursor_set_apply(C, op, event);
+      font_cursor_set_apply(C, event);
       break;
   }
   
@@ -1843,13 +1866,10 @@ void FONT_OT_selection_set(struct wmOperatorType *ot)
 /* -------------------------------------------------------------------- */
 /** \name Select Word Operator
  * \{ */
-static  font_select_word_exec(bContext *C, wmOperator *op)
+static int font_select_word_exec(bContext *C, wmOperator *UNUSED(op))
 {
-  Object *obedit = CTX_data_active_object(C);
-  Curve *cu = obedit->data;
-  EditFont *ef = cu->editfont;
-
-  move_cursor(C,PREV_WORD,false)+move_cursor(C,NEXT_WORD,true);
+  move_cursor(C,PREV_WORD,false);
+  move_cursor(C,NEXT_WORD,true);
   return OPERATOR_FINISHED; 
 }