[freetype2-demos] gsoc-2022-chariri-3 17c09dc 22/36: [ftinspect] Fix CharMap selector when the font file is symlink.

[Werner Lemberg]

branch: gsoc-2022-chariri-3
commit 17c09dca4f0f78d5ecc98da4faf66123bc3997a9
Author: Charlie Jiang <w@chariri.moe>
Commit: Charlie Jiang <w@chariri.moe>

    [ftinspect] Fix CharMap selector when the font file is symlink.
    
    When the font file is a symlink, the font will be periodically reloaded
    every 1s. When reloading, if the font's charmaps have no change, then the
    charmap selector shouldn't be re-populated, or it would be hard to change
    the current charmap.
    
    * src/ftinspect/panels/continuous.cpp: Add a guard to prevent unnecessary
      combobox repopulating.
    
    * src/ftinspect/engine/charmap.hpp: Add proper `operator==` for class
      `CharMapInfo`.
---
 src/ftinspect/engine/charmap.hpp    | 15 +++++++++++++++
 src/ftinspect/panels/continuous.cpp |  5 +++++
 2 files changed, 20 insertions(+)

diff --git a/src/ftinspect/engine/charmap.hpp b/src/ftinspect/engine/charmap.hpp
index f64d08b..a6c55e9 100644
--- a/src/ftinspect/engine/charmap.hpp
+++ b/src/ftinspect/engine/charmap.hpp
@@ -27,6 +27,21 @@ struct CharMapInfo
   QString stringifyIndex(int code, int index);
   QString stringifyIndexShort(int code);
 
+
+  friend bool
+  operator==(const CharMapInfo& lhs, const CharMapInfo& rhs)
+  {
+    return lhs.index == rhs.index && lhs.encoding == rhs.encoding;
+  }
+
+
+  friend bool
+  operator!=(const CharMapInfo& lhs, const CharMapInfo& rhs)
+  {
+    return !(lhs == rhs);
+  }
+
+
 private:
   int computeMaxIndex();
   static int maxIndexForFaceAndCharMap(FT_CharMap charMap, unsigned max);
diff --git a/src/ftinspect/panels/continuous.cpp 
b/src/ftinspect/panels/continuous.cpp
index eb82c68..284fcad 100644
--- a/src/ftinspect/panels/continuous.cpp
+++ b/src/ftinspect/panels/continuous.cpp
@@ -112,6 +112,11 @@ ContinuousTab::setGlyphBeginindex(int index)
 void
 ContinuousTab::setCharMaps(std::vector<CharMapInfo>& charMaps)
 {
+  if (charMaps_ == charMaps)
+  {
+    charMaps_ = charMaps; // Still need to substitute because ptr may differ
+    return;
+  }
   charMaps_ = charMaps;
   int oldIndex = charMapSelector_->currentIndex();
   unsigned oldEncoding = 0u;