From 508e764abaed838c440db59638ffa3bad924595d Mon Sep 17 00:00:00 2001
From: Olivier Couet <olivier.couet@cern.ch>
Date: Tue, 31 May 2016 15:26:52 +0200
Subject: [PATCH] TColor::GetFreeColorIndex() allows to make sure the new color
is created with an unused color index:
---
README/ReleaseNotes/v608/index.md | 2 ++
core/base/inc/TColor.h | 1 +
core/base/src/TColor.cxx | 23 +++++++++++++++++++++++
3 files changed, 26 insertions(+)
diff --git a/README/ReleaseNotes/v608/index.md b/README/ReleaseNotes/v608/index.md
index db2370466ec..a01d70bad15 100644
--- a/README/ReleaseNotes/v608/index.md
+++ b/README/ReleaseNotes/v608/index.md
@@ -213,6 +213,8 @@ We added a cache specifically for the fast option of the TTreeCloner to signific
* Fix two issues with the fill patterns in `TTextDump` (reported [here](https://sft.its.cern.ch/jira/browse/ROOT-8206)):
- The pattern number 3 was not implemented.
- Filled area drawn with pattern where surrounded by a solid line.
+* `TColor::GetFreeColorIndex()` allows to make sure the new color is created with an
+ unused color index:
## 3D Graphics Libraries
diff --git a/core/base/inc/TColor.h b/core/base/inc/TColor.h
index 0f8fa67bf7c..b304059bb9c 100644
--- a/core/base/inc/TColor.h
+++ b/core/base/inc/TColor.h
@@ -88,6 +88,7 @@ public:
static Int_t GetColorBright(Int_t color);
static Int_t GetColorDark(Int_t color);
static Int_t GetColorTransparent(Int_t color, Float_t a);
+ static Int_t GetFreeColorIndex();
static ULong_t Number2Pixel(Int_t ci);
static ULong_t RGB2Pixel(Int_t r, Int_t g, Int_t b);
static ULong_t RGB2Pixel(Float_t r, Float_t g, Float_t b);
diff --git a/core/base/src/TColor.cxx b/core/base/src/TColor.cxx
index b59a6d6f272..8d78a8c8756 100644
--- a/core/base/src/TColor.cxx
+++ b/core/base/src/TColor.cxx
@@ -89,6 +89,15 @@ A new color can be created the following way:
TColor *color = new TColor(ci, 0.1, 0.2, 0.3);
~~~
+\since **6.07/07:**
+TColor::GetFreeColorIndex() allows to make sure the new color is created with an
+unused color index:
+
+~~~ {.cpp}
+ Int_t ci = TColor::GetFreeColorIndex();
+ TColor *color = new TColor(ci, 0.1, 0.2, 0.3);
+~~~
+
Two sets of colors are initialized;
- The basic colors: colors with index from 0 to 50.
@@ -1863,6 +1872,20 @@ Int_t TColor::GetColorTransparent(Int_t n, Float_t a)
}
}
+////////////////////////////////////////////////////////////////////////////////
+/// Static function: Returns a free color index which can be used to define
+/// a user custom color.
+///
+/// ~~~ {.cpp}
+/// Int_t ci = TColor::GetFreeColorIndex();
+/// TColor *color = new TColor(ci, 0.1, 0.2, 0.3);
+/// ~~~
+
+Int_t TColor::GetFreeColorIndex()
+{
+ return gHighestColorIndex+1;
+}
+
////////////////////////////////////////////////////////////////////////////////
/// Static method that given a color index number, returns the corresponding
/// pixel value. This pixel value can be used in the GUI classes. This call
--
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