From 6866ef82bac864a1fb45fc7868804ceb350a94bb Mon Sep 17 00:00:00 2001
From: Bert Gijsbers <gijsbers@science.uva.nl>
Date: Thu, 26 Oct 2023 18:33:44 +0200
Subject: [PATCH] Add `supportsFormat` to check for support of additional image
 formats.

---
 src/yimage.h      |  1 +
 src/yimage2.cc    | 28 ++++++++++++++++++++++++++++
 src/yimage_gdk.cc | 21 +++++++++++++++++++++
 src/yximage.cc    | 16 ++++++++++++++++
 4 files changed, 66 insertions(+)

diff --git a/src/yimage.h b/src/yimage.h
index 344ae4b8e..426926540 100644
--- a/src/yimage.h
+++ b/src/yimage.h
@@ -26,6 +26,7 @@ class YImage: public refcounted {
     static ref<YImage> createFromIconProperty(long *pixels,
                                               unsigned width, unsigned height);
     static bool supportsDepth(unsigned depth);
+    static bool supportsFormat(const char* format);
     static const char* renderName();
 
     unsigned width() const { return fWidth; }
diff --git a/src/yimage2.cc b/src/yimage2.cc
index a687c483b..e53eb603c 100644
--- a/src/yimage2.cc
+++ b/src/yimage2.cc
@@ -38,6 +38,34 @@ bool YImage::supportsDepth(unsigned depth) {
     return depth == xapp->depth() || depth == 32;
 }
 
+#ifdef IMLIB2_VERSION
+extern "C" {
+    typedef struct _ImlibLoader ImlibLoader;
+#if IMLIB2_VERSION >= 10801
+    ImlibLoader* __imlib_FindBestLoader
+                (const char *file, const char *format, int for_save);
+#else
+    ImlibLoader* __imlib_FindBestLoaderForFormat
+                (const char *format, int for_save);
+#endif
+}
+#endif
+
+bool YImage::supportsFormat(const char* format) {
+    if ( !strcmp(format, "xpm") ||
+         !strcmp(format, "png") ||
+         !strcmp(format, "jpg") )
+         return true;
+#ifdef IMLIB2_VERSION
+#if IMLIB2_VERSION >= 10801
+    return __imlib_FindBestLoader(nullptr, format, 0) != nullptr;
+#else
+    return __imlib_FindBestLoaderForFormat(format, 0) != nullptr;
+#endif
+#endif
+    return false;
+}
+
 bool YImage2::hasAlpha() const {
     context();
     return imlib_image_has_alpha();
diff --git a/src/yimage_gdk.cc b/src/yimage_gdk.cc
index bc1b243a3..11dcd2731 100644
--- a/src/yimage_gdk.cc
+++ b/src/yimage_gdk.cc
@@ -14,6 +14,27 @@ bool YImage::supportsDepth(unsigned depth) {
     return depth == unsigned(xlib_rgb_get_depth());
 }
 
+bool YImage::supportsFormat(const char* format) {
+    if ( !strcmp(format, "xpm") ||
+         !strcmp(format, "png") ||
+         !strcmp(format, "jpg") )
+         return true;
+
+    bool supports = false;
+    GSList* formats = gdk_pixbuf_get_formats();
+    int length = g_slist_length(formats);
+    for (int i = 0; i < length && supports == false; i++) {
+        GdkPixbufFormat* info = (GdkPixbufFormat *) g_slist_nth_data(formats, i);
+        gchar** exts = gdk_pixbuf_format_get_extensions(info);
+        for (gchar** p = exts; *p && supports == false; ++p) {
+            supports = (strcmp(*p, format) == 0);
+        }
+        g_strfreev(exts);
+    }
+    g_slist_free(formats);
+    return supports;
+}
+
 bool YImageGDK::hasAlpha() const {
     return gdk_pixbuf_get_has_alpha(fPixbuf);
 }
diff --git a/src/yximage.cc b/src/yximage.cc
index d9fa564b6..fd294d526 100644
--- a/src/yximage.cc
+++ b/src/yximage.cc
@@ -136,6 +136,22 @@ bool YImage::supportsDepth(unsigned depth) {
     return depth == 32 || depth == xapp->depth();
 }
 
+bool YImage::supportsFormat(const char* format) {
+    if (strcmp(format, "xbm") == 0)
+        return true;
+    else if (strcmp(format, "xpm") == 0)
+        return true;
+#ifdef CONFIG_LIBPNG
+    else if (strcmp(format, "png") == 0)
+        return true;
+#endif
+#ifdef CONFIG_LIBJPEG
+    else if (strcmp(format, "jpg") == 0 || strcmp(format, "jpeg") == 0)
+        return true;
+#endif
+    return false;
+}
+
 ref<YImage> YImage::load(upath filename)
 {
     ref<YImage> image;