Introduce supportedModes bit mask for meters

This allows meters to limit the available display modes/styles
based on a bit mask for each meter class. Doing so allows to
disable display modes that make little or no sense for a
specific meter.

Co-authored-by: Benny Baumann <BenBE@geshi.org>
Co-authored-by: Kang-Che Sung <explorer09@gmail.com>

Author: Explorer09

Meter.c

@@ -24,6 +24,10 @@ in the source distribution for its full text.
 #include "XUtils.h"
 
 
+#ifndef UINT32_WIDTH
+#define UINT32_WIDTH 32
+#endif
+
 #define GRAPH_HEIGHT 4 /* Unit: rows (lines) */
 
 typedef struct MeterMode_ {
@@ -380,7 +384,9 @@ Meter* Meter_new(const Machine* host, unsigned int param, const MeterClass* type
    if (Meter_initFn(this)) {
       Meter_init(this);
    }
+
    Meter_setMode(this, type->defaultMode);
+   assert(this->mode > 0);
    return this;
 }
 
@@ -439,21 +445,28 @@ void Meter_setCaption(Meter* this, const char* caption) {
 }
 
 void Meter_setMode(Meter* this, MeterModeId modeIndex) {
-   if (modeIndex > 0 && modeIndex == this->mode) {
+   if (modeIndex == this->mode) {
+      assert(this->mode > 0);
       return;
    }
 
-   if (modeIndex == 0) {
-      modeIndex = 1;
+   uint32_t supportedModes = Meter_supportedModes(this);
+   if (!supportedModes) {
+      supportedModes = METERMODE_DEFAULT_SUPPORTED;
    }
+   assert(supportedModes);
+   assert(!(supportedModes & (1 << 0)));
 
-   assert(modeIndex < LAST_METERMODE);
+   assert(LAST_METERMODE <= UINT32_WIDTH);
+   if (modeIndex >= LAST_METERMODE || !(supportedModes & (1UL << modeIndex)))
+      return;
+
+   assert(modeIndex >= 1);
    if (Meter_updateModeFn(this)) {
       assert(Meter_drawFn(this));
       this->draw = Meter_drawFn(this);
       Meter_updateMode(this, modeIndex);
    } else {
-      assert(modeIndex >= 1);
       free(this->drawData.values);
       this->drawData.values = NULL;
       this->drawData.nValues = 0;
@@ -465,6 +478,23 @@ void Meter_setMode(Meter* this, MeterModeId modeIndex) {
    this->mode = modeIndex;
 }
 
+MeterModeId Meter_nextSupportedMode(const Meter* this) {
+   uint32_t supportedModes = Meter_supportedModes(this);
+   if (!supportedModes) {
+      supportedModes = METERMODE_DEFAULT_SUPPORTED;
+   }
+   assert(supportedModes);
+
+   assert(this->mode < UINT32_WIDTH);
+   uint32_t modeMask = ((uint32_t)-1 << 1) << this->mode;
+   uint32_t nextModes = supportedModes & modeMask;
+   if (!nextModes) {
+      nextModes = supportedModes;
+   }
+
+   return (MeterModeId)countTrailingZeros(nextModes);
+}
+
 ListItem* Meter_toListItem(const Meter* this, bool moving) {
    char mode[20];
    if (this->mode > 0) {

Meter.h

@@ -65,6 +65,7 @@ typedef struct MeterClass_ {
    const Meter_GetCaption getCaption;
    const Meter_GetUiName getUiName;
    const MeterModeId defaultMode;
+   const uint32_t supportedModes;          /* bitset of supported modes, 1<<mode_id */
    const double total;
    const int* const attributes;
    const char* const name;                 /* internal name of the meter, must not contain any space */
@@ -88,6 +89,7 @@ typedef struct MeterClass_ {
 #define Meter_getUiName(this_,n_,l_)   As_Meter(this_)->getUiName((const Meter*)(this_),n_,l_)
 #define Meter_getCaptionFn(this_)      As_Meter(this_)->getCaption
 #define Meter_getCaption(this_)        (Meter_getCaptionFn(this_) ? As_Meter(this_)->getCaption((const Meter*)(this_)) : (this_)->caption)
+#define Meter_supportedModes(this_)    As_Meter(this_)->supportedModes
 #define Meter_attributes(this_)        As_Meter(this_)->attributes
 #define Meter_name(this_)              As_Meter(this_)->name
 #define Meter_uiName(this_)            As_Meter(this_)->uiName
@@ -139,6 +141,8 @@ void Meter_setCaption(Meter* this, const char* caption);
 
 void Meter_setMode(Meter* this, MeterModeId modeIndex);
 
+MeterModeId Meter_nextSupportedMode(const Meter* this);
+
 ListItem* Meter_toListItem(const Meter* this, bool moving);
 
 extern const MeterClass BlankMeter_class;

MeterMode.h

@@ -19,4 +19,11 @@ enum MeterModeId_ {
 
 typedef unsigned int MeterModeId;
 
+#define METERMODE_DEFAULT_SUPPORTED ( \
+   (1 << BAR_METERMODE) |             \
+   (1 << TEXT_METERMODE) |            \
+   (1 << GRAPH_METERMODE) |           \
+   (1 << LED_METERMODE) |             \
+   0) // Avoids edits when updating
+
 #endif

MetersPanel.c

@@ -108,9 +108,7 @@ static HandlerResult MetersPanel_eventHandler(Panel* super, int ch) {
          if (!Vector_size(this->meters))
             break;
          Meter* meter = (Meter*) Vector_get(this->meters, selected);
-         MeterModeId mode = meter->mode + 1;
-         if (mode == LAST_METERMODE)
-            mode = 1;
+         MeterModeId mode = Meter_nextSupportedMode(meter);
          Meter_setMode(meter, mode);
          Panel_set(super, selected, (Object*) Meter_toListItem(meter, this->moving));
          result = HANDLED;