From d734f2872745dd1ab5aab9dafb144130d7e9fdcc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Novomesk=C3=BD?= <dnovomesky@gmail.com>
Date: Tue, 18 Oct 2022 15:20:16 +0200
Subject: [PATCH] jxl: indicate when all frames have been read

and return correct loop count
---
 src/imageformats/jxl.cpp | 23 ++++++++++++++++++++---
 src/imageformats/jxl_p.h |  1 +
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/src/imageformats/jxl.cpp b/src/imageformats/jxl.cpp
index da2cd2e..2501086 100644
--- a/src/imageformats/jxl.cpp
+++ b/src/imageformats/jxl.cpp
@@ -48,6 +48,11 @@ bool QJpegXLHandler::canRead() const
 
     if (m_parseState != ParseJpegXLError) {
         setFormat("jxl");
+
+        if (m_parseState == ParseJpegXLFinished) {
+            return false;
+        }
+
         return true;
     }
     return false;
@@ -72,7 +77,7 @@ bool QJpegXLHandler::canRead(QIODevice *device)
 
 bool QJpegXLHandler::ensureParsed() const
 {
-    if (m_parseState == ParseJpegXLSuccess || m_parseState == ParseJpegXLBasicInfoParsed) {
+    if (m_parseState == ParseJpegXLSuccess || m_parseState == ParseJpegXLBasicInfoParsed || m_parseState == ParseJpegXLFinished) {
         return true;
     }
     if (m_parseState == ParseJpegXLError) {
@@ -90,7 +95,7 @@ bool QJpegXLHandler::ensureALLCounted() const
         return false;
     }
 
-    if (m_parseState == ParseJpegXLSuccess) {
+    if (m_parseState == ParseJpegXLSuccess || m_parseState == ParseJpegXLFinished) {
         return true;
     }
 
@@ -401,7 +406,15 @@ bool QJpegXLHandler::decode_one_frame()
             if (!rewind()) {
                 return false;
             }
+
+            // all frames in animation have been read
+            m_parseState = ParseJpegXLFinished;
+        } else {
+            m_parseState = ParseJpegXLSuccess;
         }
+    } else {
+        // the static image has been read
+        m_parseState = ParseJpegXLFinished;
     }
 
     return true;
@@ -860,6 +873,7 @@ bool QJpegXLHandler::jumpToNextImage()
         }
     }
 
+    m_parseState = ParseJpegXLSuccess;
     return true;
 }
 
@@ -874,12 +888,14 @@ bool QJpegXLHandler::jumpToImage(int imageNumber)
     }
 
     if (imageNumber == m_currentimage_index) {
+        m_parseState = ParseJpegXLSuccess;
         return true;
     }
 
     if (imageNumber > m_currentimage_index) {
         JxlDecoderSkipFrames(m_decoder, imageNumber - m_currentimage_index);
         m_currentimage_index = imageNumber;
+        m_parseState = ParseJpegXLSuccess;
         return true;
     }
 
@@ -891,6 +907,7 @@ bool QJpegXLHandler::jumpToImage(int imageNumber)
         JxlDecoderSkipFrames(m_decoder, imageNumber);
     }
     m_currentimage_index = imageNumber;
+    m_parseState = ParseJpegXLSuccess;
     return true;
 }
 
@@ -914,7 +931,7 @@ int QJpegXLHandler::loopCount() const
     }
 
     if (m_basicinfo.have_animation) {
-        return 1;
+        return (m_basicinfo.animation.num_loops > 0) ? m_basicinfo.animation.num_loops - 1 : -1;
     } else {
         return 0;
     }
diff --git a/src/imageformats/jxl_p.h b/src/imageformats/jxl_p.h
index 8339d7e..7a4af0b 100644
--- a/src/imageformats/jxl_p.h
+++ b/src/imageformats/jxl_p.h
@@ -57,6 +57,7 @@ private:
         ParseJpegXLNotParsed = 0,
         ParseJpegXLSuccess = 1,
         ParseJpegXLBasicInfoParsed = 2,
+        ParseJpegXLFinished = 3,
     };
 
     ParseJpegXLState m_parseState;
-- 
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