Introduce isPercentChart member in MeterClass

This property distinguishes meters that have a (relatively) fixed
"total" value and meters that do not have a definite maximum value.
The former meters would be drawn as a "100% stacked bar" or "graph", and
the latter could have their "total" values updated automatically in bar
meter mode.

This commit is a prerequisite for the feature "Graph meter dynamic
scaling and percent graph drawing".

Signed-off-by: Kang-Che Sung <explorer09@gmail.com>

Author: Explorer09

BatteryMeter.c

@@ -64,6 +64,7 @@ const MeterClass BatteryMeter_class = {
    .defaultMode = TEXT_METERMODE,
    .supportedModes = METERMODE_DEFAULT_SUPPORTED,
    .maxItems = 1,
+   .isPercentChart = true,
    .total = 100.0,
    .attributes = BatteryMeter_attributes,
    .name = "Battery",

CPUMeter.c

@@ -352,6 +352,7 @@ const MeterClass CPUMeter_class = {
    .defaultMode = BAR_METERMODE,
    .supportedModes = METERMODE_DEFAULT_SUPPORTED,
    .maxItems = CPU_METER_ITEMCOUNT,
+   .isPercentChart = true,
    .total = 100.0,
    .attributes = CPUMeter_attributes,
    .name = "CPU",

DiskIOMeter.c

@@ -158,6 +158,7 @@ const MeterClass DiskIOMeter_class = {
    .defaultMode = TEXT_METERMODE,
    .supportedModes = METERMODE_DEFAULT_SUPPORTED,
    .maxItems = 1,
+   .isPercentChart = true,
    .total = 1.0,
    .attributes = DiskIOMeter_attributes,
    .name = "DiskIO",

FileDescriptorMeter.c

@@ -110,6 +110,7 @@ const MeterClass FileDescriptorMeter_class = {
    .defaultMode = TEXT_METERMODE,
    .supportedModes = METERMODE_DEFAULT_SUPPORTED,
    .maxItems = 2,
+   .isPercentChart = false,
    .total = 65536.0,
    .attributes = FileDescriptorMeter_attributes,
    .name = "FileDescriptors",

GPUMeter.c

@@ -156,6 +156,7 @@ const MeterClass GPUMeter_class = {
    .defaultMode = BAR_METERMODE,
    .supportedModes = METERMODE_DEFAULT_SUPPORTED,
    .maxItems = ARRAYSIZE(GPUMeter_attributes),
+   .isPercentChart = true,
    .total = 100.0,
    .attributes = GPUMeter_attributes,
    .name = "GPU",

LoadAverageMeter.c

@@ -111,6 +111,7 @@ const MeterClass LoadAverageMeter_class = {
    .defaultMode = TEXT_METERMODE,
    .supportedModes = METERMODE_DEFAULT_SUPPORTED,
    .maxItems = 3,
+   .isPercentChart = false,
    .total = 100.0,
    .attributes = LoadAverageMeter_attributes,
    .name = "LoadAverage",
@@ -129,6 +130,7 @@ const MeterClass LoadMeter_class = {
    .defaultMode = TEXT_METERMODE,
    .supportedModes = METERMODE_DEFAULT_SUPPORTED,
    .maxItems = 1,
+   .isPercentChart = false,
    .total = 100.0,
    .attributes = LoadMeter_attributes,
    .name = "Load",

MemoryMeter.c

@@ -117,6 +117,7 @@ const MeterClass MemoryMeter_class = {
    .defaultMode = BAR_METERMODE,
    .supportedModes = METERMODE_DEFAULT_SUPPORTED,
    .maxItems = MEMORY_METER_ITEMCOUNT,
+   .isPercentChart = true,
    .total = 100.0,
    .attributes = MemoryMeter_attributes,
    .name = "Memory",

Meter.h

@@ -75,6 +75,12 @@ typedef struct MeterClass_ {
    const char* const description;          /* optional meter description in header setup menu */
    const uint8_t maxItems;
    const bool isMultiColumn;               /* whether the meter draws multiple sub-columns (defaults to false) */
+
+   /* Specifies how the meter is rendered in bar or graph mode:
+      true: a percent bar or graph with 'total' representing 100% or maximum.
+      false: the meter has no definite maximum; 'total' repesents initial
+      maximum value while actual maximum is updated automatically. */
+   const bool isPercentChart;
 } MeterClass;
 
 #define As_Meter(this_)                ((const MeterClass*)((this_)->super.klass))
@@ -95,6 +101,7 @@ typedef struct MeterClass_ {
 #define Meter_name(this_)              As_Meter(this_)->name
 #define Meter_uiName(this_)            As_Meter(this_)->uiName
 #define Meter_isMultiColumn(this_)     As_Meter(this_)->isMultiColumn
+#define Meter_isPercentChart(this_)    As_Meter(this_)->isPercentChart
 
 typedef struct GraphData_ {
    struct timeval time;

NetworkIOMeter.c

@@ -171,6 +171,7 @@ const MeterClass NetworkIOMeter_class = {
    .defaultMode = TEXT_METERMODE,
    .supportedModes = METERMODE_DEFAULT_SUPPORTED,
    .maxItems = 2,
+   .isPercentChart = false,
    .total = 100.0,
    .attributes = NetworkIOMeter_attributes,
    .name = "NetworkIO",

SwapMeter.c

@@ -75,6 +75,7 @@ const MeterClass SwapMeter_class = {
    .defaultMode = BAR_METERMODE,
    .supportedModes = METERMODE_DEFAULT_SUPPORTED,
    .maxItems = SWAP_METER_ITEMCOUNT,
+   .isPercentChart = true,
    .total = 100.0,
    .attributes = SwapMeter_attributes,
    .name = "Swap",