add onStyleImageMissing to allow dynamically loaded or generated images (#14253)

Also make `Style#updateImage(...)` much faster when the image doesn't change size. This can be useful for asynchronously generating images.

2 files changed, 6 insertions, 0 deletions

diff --git a/include/mbgl/map/map_observer.hpp b/include/mbgl/map/map_observer.hpp
index 8ad9e93d0b..75e389df9f 100644
--- a/include/mbgl/map/map_observer.hpp
+++ b/include/mbgl/map/map_observer.hpp
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <mbgl/style/source.hpp>
+#include <mbgl/style/image.hpp>
 
 #include <cstdint>
 #include <string>
@@ -46,6 +47,7 @@ public:
     virtual void onDidFinishLoadingStyle() {}
     virtual void onSourceChanged(style::Source&) {}
     virtual void onDidBecomeIdle() {}
+    virtual void onStyleImageMissing(const std::string&) {}
 };
 
 } // namespace mbgl
diff --git a/include/mbgl/renderer/renderer_observer.hpp b/include/mbgl/renderer/renderer_observer.hpp
index 0a76d01ca7..1a9d3ff9bc 100644
--- a/include/mbgl/renderer/renderer_observer.hpp
+++ b/include/mbgl/renderer/renderer_observer.hpp
@@ -31,6 +31,10 @@ public:
 
     // Final frame
     virtual void onDidFinishRenderingMap() {}
+
+    // Style is missing an image
+    using StyleImageMissingCallback = std::function<void()>;
+    virtual void onStyleImageMissing(const std::string&, StyleImageMissingCallback done) { done(); }
 };
 
 } // namespace mbgl