Support dynamic screens with 'top-most' entities beyond processes

This implements our concept of 'dynamic screens' in htop, with a
first use-case of pcp-htop displaying things like top-filesystem
and top-cgroups under new screen tabs.  However the idea is more
general than use in pcp-htop and we've paved the way here for us
to collectively build mroe general tabular screens in core htop,
as well.

From the pcp-htop side of things, dynamic screens are configured
using text-based configuration files that define the mapping for
PCP metrics to columns (and metric instances to rows).  Metrics
are defined either directly (via metric names) or indirectly via
PCP derived metric specifications.  Value scaling and the units
displayed is automatic based on PCP metric units and data types.

This commit represents a collaborative effort of several months,
primarily between myself, Nathan and BenBE.

Signed-off-by: Sohaib Mohamed <sohaib.amhmd@gmail.com>
Signed-off-by: Nathan Scott <nathans@redhat.com>

1 files changed, 12 insertions, 11 deletions

diff --git a/ScreensPanel.c b/ScreensPanel.c
index cb664ac4..d0038809 100644
--- a/ScreensPanel.c
+++ b/ScreensPanel.c
@@ -1,7 +1,7 @@
 /*
 htop - ScreensPanel.c
 (C) 2004-2011 Hisham H. Muhammad
-(C) 2020-2022 htop dev team
+(C) 2020-2023 htop dev team
 Released under the GNU GPLv2+, see the COPYING file
 in the source distribution for its full text.
 */
@@ -12,6 +12,7 @@ in the source distribution for its full text.
 #include <ctype.h>
 #include <string.h>
 
+#include "AvailableColumnsPanel.h"
 #include "CRT.h"
 #include "FunctionBar.h"
 #include "Hashtable.h"
@@ -43,6 +44,7 @@ ScreenListItem* ScreenListItem_new(const char* value, ScreenSettings* ss) {
 }
 
 static const char* const ScreensFunctions[] = {"      ", "Rename", "      ", "      ", "New   ", "      ", "MoveUp", "MoveDn", "Remove", "Done  ", NULL};
+static const char* const DynamicFunctions[] = {"      ", "Rename", "      ", "      ", "      ", "      ", "MoveUp", "MoveDn", "Remove", "Done  ", NULL};
 
 static void ScreensPanel_delete(Object* object) {
    Panel* super = (Panel*) object;
@@ -55,11 +57,6 @@ static void ScreensPanel_delete(Object* object) {
       item->ss = NULL;
    }
 
-   /* during renaming the ListItem's value points to our static buffer */
-   if (this->renamingItem)
-      this->renamingItem->value = this->saved;
-
-   Panel_done(super);
    free(this);
 }
 
@@ -212,6 +209,8 @@ static HandlerResult ScreensPanel_eventHandlerNormal(Panel* super, int ch) {
       case KEY_F(5):
       case KEY_CTRL('N'):
       {
+         if (this->settings->dynamicScreens)
+            break;
          addNewScreen(super);
          startRenaming(super);
          shouldRebuildArray = true;
@@ -272,7 +271,9 @@ static HandlerResult ScreensPanel_eventHandlerNormal(Panel* super, int ch) {
    }
    ScreenListItem* newFocus = (ScreenListItem*) Panel_getSelected(super);
    if (newFocus && oldFocus != newFocus) {
-      ColumnsPanel_fill(this->columns, newFocus->ss, this->settings->dynamicColumns);
+      Hashtable* dynamicColumns = this->settings->dynamicColumns;
+      ColumnsPanel_fill(this->columns, newFocus->ss, dynamicColumns);
+      AvailableColumnsPanel_fill(this->availableColumns, newFocus->ss->dynamic, dynamicColumns);
       result = HANDLED;
    }
    if (shouldRebuildArray)
@@ -304,11 +305,12 @@ ScreensPanel* ScreensPanel_new(Settings* settings) {
    ScreensPanel* this = AllocThis(ScreensPanel);
    Panel* super = (Panel*) this;
    Hashtable* columns = settings->dynamicColumns;
-   FunctionBar* fuBar = FunctionBar_new(ScreensFunctions, NULL, NULL);
+   FunctionBar* fuBar = FunctionBar_new(settings->dynamicScreens ? DynamicFunctions : ScreensFunctions, NULL, NULL);
    Panel_init(super, 1, 1, 1, 1, Class(ListItem), true, fuBar);
 
    this->settings = settings;
    this->columns = ColumnsPanel_new(settings->screens[0], columns, &(settings->changed));
+   this->availableColumns = AvailableColumnsPanel_new((Panel*) this->columns, columns);
    this->moving = false;
    this->renamingItem = NULL;
    super->cursorOn = false;
@@ -317,7 +319,7 @@ ScreensPanel* ScreensPanel_new(Settings* settings) {
 
    for (unsigned int i = 0; i < settings->nScreens; i++) {
       ScreenSettings* ss = settings->screens[i];
-      char* name = ss->name;
+      char* name = ss->heading;
       Panel_add(super, (Object*) ScreenListItem_new(name, ss));
    }
    return this;
@@ -332,9 +334,8 @@ void ScreensPanel_update(Panel* super) {
    for (int i = 0; i < size; i++) {
       ScreenListItem* item = (ScreenListItem*) Panel_get(super, i);
       ScreenSettings* ss = item->ss;
-      free(ss->name);
+      free_and_xStrdup(&ss->heading, ((ListItem*) item)->value);
       this->settings->screens[i] = ss;
-      ss->name = xStrdup(((ListItem*) item)->value);
    }
    this->settings->screens[size] = NULL;
 }