handle clicks on panel header line

Action.c

@@ -154,7 +154,7 @@ static bool expandCollapse(Panel* panel) {
    return true;
 }
 
-static inline Htop_Reaction setSortKey(Settings* settings, ProcessField sortKey) {
+Htop_Reaction Action_setSortKey(Settings* settings, ProcessField sortKey) {
    settings->sortKey = sortKey;
    settings->direction = 1;
    settings->treeView = false;
@@ -175,7 +175,7 @@ static Htop_Reaction sortBy(State* st) {
    }
    ListItem* field = (ListItem*) Action_pickFromVector(st, sortPanel, 15);
    if (field) {
-      reaction |= setSortKey(st->settings, field->key);
+      reaction |= Action_setSortKey(st->settings, field->key);
    }
    Object_delete(sortPanel);
    return reaction | HTOP_REFRESH | HTOP_REDRAW_BAR | HTOP_UPDATE_PANELHDR;
@@ -189,15 +189,15 @@ static Htop_Reaction actionResize(State* st) {
 }
 
 static Htop_Reaction actionSortByMemory(State* st) {
-   return setSortKey(st->settings, PERCENT_MEM);
+   return Action_setSortKey(st->settings, PERCENT_MEM);
 }
 
 static Htop_Reaction actionSortByCPU(State* st) {
-   return setSortKey(st->settings, PERCENT_CPU);
+   return Action_setSortKey(st->settings, PERCENT_CPU);
 }
 
 static Htop_Reaction actionSortByTime(State* st) {
-   return setSortKey(st->settings, TIME);
+   return Action_setSortKey(st->settings, TIME);
 }
 
 static Htop_Reaction actionToggleKernelThreads(State* st) {

Action.h

@@ -45,6 +45,8 @@ Object* Action_pickFromVector(State* st, Panel* list, int x);
 
 bool Action_setUserOnly(const char* userName, uid_t* userId);
 
+Htop_Reaction Action_setSortKey(Settings* settings, ProcessField sortKey);
+
 // ----------------------------------------
 
 void Action_setBindings(Htop_Action* keys);

CategoriesPanel.c

@@ -78,7 +78,7 @@ static HandlerResult CategoriesPanel_eventHandler(Panel* super, int ch) {
 
    int selected = Panel_getSelectedIndex(super);
    switch (ch) {
-      case EVENT_SETSELECTED:
+      case EVENT_SET_SELECTED:
          result = HANDLED;
          break;
       case KEY_UP:

MainPanel.c

@@ -67,7 +67,21 @@ static HandlerResult MainPanel_eventHandler(Panel* super, int ch) {
    
    Htop_Reaction reaction = HTOP_OK;
 
-   if (ch != ERR && this->inc->active) {
+   if (EVENT_IS_HEADER_CLICK(ch)) {
+      int x = EVENT_HEADER_CLICK_GET_X(ch);
+      ProcessList* pl = this->state->pl;
+      Settings* settings = this->state->settings;
+      int hx = super->scrollH + x + 1;
+      ProcessField field = ProcessList_keyAt(pl, hx);
+      if (field == settings->sortKey) {
+         Settings_invertSortOrder(settings);
+         settings->treeView = false;
+      } else {
+         reaction |= Action_setSortKey(settings, field);
+      }
+      reaction |= HTOP_RECALCULATE;
+      result = HANDLED;
+   } else if (ch != ERR && this->inc->active) {
       bool filterChanged = IncSet_handleKey(this->inc, ch, super, (IncMode_GetPanelValue) MainPanel_getValue, NULL);
       if (filterChanged) {
          this->state->pl->incFilter = IncSet_filter(this->inc);

Panel.c

@@ -37,7 +37,11 @@ typedef enum HandlerResult_ {
    SYNTH_KEY   = 0x20,
 } HandlerResult;
 
-#define EVENT_SETSELECTED -1
+#define EVENT_SET_SELECTED -1
+
+#define EVENT_HEADER_CLICK(x_) (-10000 + x_)
+#define EVENT_IS_HEADER_CLICK(ev_) (ev_ >= -10000 && ev_ <= -9000)
+#define EVENT_HEADER_CLICK_GET_X(ev_) (ev_ + 10000)
 
 typedef HandlerResult(*Panel_EventHandler)(Panel*, int);
 
@@ -88,7 +92,7 @@ PanelClass Panel_class = {
       .extends = Class(Object),
       .delete = Panel_delete
    },
-   .eventHandler = Panel_selectByTyping
+   .eventHandler = Panel_selectByTyping,
 };
 
 Panel* Panel_new(int x, int y, int w, int h, bool owner, ObjectClass* type, FunctionBar* fuBar) {
@@ -250,7 +254,7 @@ void Panel_setSelected(Panel* this, int selected) {
       selected = 0;
    this->selected = selected;
    if (Panel_eventHandlerFn(this)) {
-      Panel_eventHandler(this, EVENT_SETSELECTED);
+      Panel_eventHandler(this, EVENT_SET_SELECTED);
    }
 }
 

Panel.h

@@ -26,7 +26,11 @@ typedef enum HandlerResult_ {
    SYNTH_KEY   = 0x20,
 } HandlerResult;
 
-#define EVENT_SETSELECTED -1
+#define EVENT_SET_SELECTED -1
+
+#define EVENT_HEADER_CLICK(x_) (-10000 + x_)
+#define EVENT_IS_HEADER_CLICK(ev_) (ev_ >= -10000 && ev_ <= -9000)
+#define EVENT_HEADER_CLICK_GET_X(ev_) (ev_ + 10000)
 
 typedef HandlerResult(*Panel_EventHandler)(Panel*, int);
 

ScreenManager.c

@@ -190,7 +190,9 @@ void ScreenManager_run(ScreenManager* this, Panel** lastFocus, int* lastKey) {
       int prevCh = ch;
       ch = getch();
 
+      HandlerResult result = IGNORED;
       if (ch == KEY_MOUSE) {
+         ch = ERR;
          MEVENT mevent;
          int ok = getmouse(&mevent);
          if (ok == OK) {
@@ -199,39 +201,24 @@ void ScreenManager_run(ScreenManager* this, Panel** lastFocus, int* lastKey) {
             } else {
                for (int i = 0; i < this->panelCount; i++) {
                   Panel* panel = (Panel*) Vector_get(this->panels, i);
-                  if (mevent.x > panel->x && mevent.x <= panel->x+panel->w &&
-                     mevent.y > panel->y && mevent.y <= panel->y+panel->h &&
-                     (this->allowFocusChange || panelFocus == panel) ) {
-                     focus = i;
-                     panelFocus = setCurrentPanel(panel);
-                     Panel_setSelected(panel, mevent.y - panel->y + panel->scrollV - 1);
-                     break;
+                  if (mevent.x >= panel->x && mevent.x <= panel->x+panel->w) {
+                     if (mevent.y == panel->y) {
+                        ch = EVENT_HEADER_CLICK(mevent.x - panel->x);
+                        break;
+                     } else if (mevent.y > panel->y && mevent.y <= panel->y+panel->h) {
+                        if (panel == panelFocus || this->allowFocusChange) {
+                           focus = i;
+                           panelFocus = setCurrentPanel(panel);
+                           Panel_setSelected(panel, mevent.y - panel->y + panel->scrollV - 1);
+                        }
+                        ch = KEY_MOUSE;
+                        break;
+                     }
                   }
                }
             }
          }
       }
-      if (Panel_eventHandlerFn(panelFocus)) {
-         HandlerResult result = Panel_eventHandler(panelFocus, ch);
-         if (result & SYNTH_KEY) {
-            ch = result >> 16;
-         }
-         if (result & REDRAW) {
-            //redraw = true;
-            sortTimeout = 0;
-         }
-         if (result & RESCAN) {
-            rescan = true;
-            sortTimeout = 0;
-         }
-         if (result & HANDLED) {
-            redraw = true;
-            continue;
-         } else if (result & BREAK_LOOP) {
-            quit = true;
-            continue;
-         }
-      }
       if (ch == ERR) {
          sortTimeout--;
          if (prevCh == ch && !timedOut) {
@@ -245,6 +232,25 @@ void ScreenManager_run(ScreenManager* this, Panel** lastFocus, int* lastKey) {
          continue;
       }
       redraw = true;
+      if (Panel_eventHandlerFn(panelFocus)) {
+         result = Panel_eventHandler(panelFocus, ch);
+      }
+      if (result & SYNTH_KEY) {
+         ch = result >> 16;
+      }
+      if (result & REDRAW) {
+         sortTimeout = 0;
+      }
+      if (result & RESCAN) {
+         rescan = true;
+         sortTimeout = 0;
+      }
+      if (result & HANDLED) {
+         continue;
+      } else if (result & BREAK_LOOP) {
+         quit = true;
+         continue;
+      }
       
       switch (ch) {
       case KEY_RESIZE: