DisplayOptions: "Inc"/"Dec" operations in the function bar

For numeric entries in Display Options, this gives users a
hint of which keys operate on the value, and allows the
value to be increasable/decreasable using the mouse as well.

Author: hishamhm

CommandLine.c

@@ -32,6 +32,7 @@ in the source distribution for its full text.
 #include "Machine.h"
 #include "MainPanel.h"
 #include "MetersPanel.h"
+#include "DisplayOptionsPanel.h"
 #include "Panel.h"
 #include "Platform.h"
 #include "Process.h"
@@ -425,6 +426,7 @@ int CommandLine_run(int argc, char** argv) {
 
    ScreenManager_delete(scr);
    MetersPanel_cleanup();
+   DisplayOptionsPanel_cleanup();
 
    UsersTable_delete(ut);
 

DisplayOptionsPanel.c

@@ -24,6 +24,18 @@ in the source distribution for its full text.
 
 static const char* const DisplayOptionsFunctions[] = {"      ", "      ", "      ", "      ", "      ", "      ", "      ", "      ", "      ", "Done  ", NULL};
 
+static const char* const DisplayOptionsIncDecFunctions[] = {"Inc   ", "Dec   ", "                                                      ", "Done  ", NULL};
+static const char* const DisplayOptionsIncDecKeys[] = {"+ ", "- ", "  ", "F10", NULL};
+static const int DisplayOptionsIncDecEvents[] = {'+', '-', ERR, KEY_F(10)};
+static FunctionBar*  DisplayOptions_incDecBar = NULL;
+
+void DisplayOptionsPanel_cleanup(void) {
+   if (DisplayOptions_incDecBar) {
+      FunctionBar_delete(DisplayOptions_incDecBar);
+      DisplayOptions_incDecBar = NULL;
+   }
+}
+
 static void DisplayOptionsPanel_delete(Object* object) {
    Panel* super = (Panel*) object;
    DisplayOptionsPanel* this = (DisplayOptionsPanel*) object;
@@ -73,6 +85,28 @@ static HandlerResult DisplayOptionsPanel_eventHandler(Panel* super, int ch) {
             result = HANDLED;
          }
          break;
+      case KEY_UP:
+      case KEY_DOWN:
+      case KEY_NPAGE:
+      case KEY_PPAGE:
+      case KEY_HOME:
+      case KEY_END:
+         {
+            OptionItem* previous = selected;
+            Panel_onKey(super, ch);
+            selected = (OptionItem*) Panel_getSelected(super);
+            if (previous != selected) {
+               result = HANDLED;
+            }
+         }
+         /* fallthrough */
+      case EVENT_SET_SELECTED:
+         if (OptionItem_kind(selected) == OPTION_ITEM_NUMBER) {
+            super->currentBar = DisplayOptions_incDecBar;
+         } else {
+            Panel_setDefaultBar(super);
+         }
+         break;
    }
 
    if (result == HANDLED) {
@@ -104,6 +138,10 @@ DisplayOptionsPanel* DisplayOptionsPanel_new(Settings* settings, ScreenManager*
    FunctionBar* fuBar = FunctionBar_new(DisplayOptionsFunctions, NULL, NULL);
    Panel_init(super, 1, 1, 1, 1, Class(OptionItem), true, fuBar);
 
+   if (!DisplayOptions_incDecBar) {
+      DisplayOptions_incDecBar = FunctionBar_new(DisplayOptionsIncDecFunctions, DisplayOptionsIncDecKeys, DisplayOptionsIncDecEvents);
+   }
+
    this->settings = settings;
    this->scr = scr;
 

DisplayOptionsPanel.h

@@ -21,6 +21,8 @@ typedef struct DisplayOptionsPanel_ {
 
 extern const PanelClass DisplayOptionsPanel_class;
 
+void DisplayOptionsPanel_cleanup(void);
+
 DisplayOptionsPanel* DisplayOptionsPanel_new(Settings* settings, ScreenManager* scr);
 
 #endif