LibGfx: Use NonnullRefPtr<Bitmap> for frame descriptors

This makes it a bit easier to reason about where bitmaps should be
available.

Libraries/LibGfx/ImageFormats/BMPLoader.cpp

@@ -1547,7 +1547,7 @@ ErrorOr<ImageFrameDescriptor> BMPImageDecoderPlugin::frame(size_t index, Optiona
         TRY(decode_bmp_pixel_data(*m_context));
 
     VERIFY(m_context->bitmap);
-    return ImageFrameDescriptor { m_context->bitmap, 0 };
+    return ImageFrameDescriptor { *m_context->bitmap, 0 };
 }
 
 ErrorOr<Optional<ReadonlyBytes>> BMPImageDecoderPlugin::icc_data()

Libraries/LibGfx/ImageFormats/GIFLoader.cpp

@@ -488,20 +488,20 @@ ErrorOr<ImageFrameDescriptor> GIFImageDecoderPlugin::frame(size_t index, Optiona
             m_context->error_state = GIFLoadingContext::ErrorState::FailedToDecodeAnyFrame;
             return result.release_error();
         }
-        if (auto result = decode_frame(*m_context, 0); result.is_error()) {
+        if (result = decode_frame(*m_context, 0); result.is_error()) {
             m_context->error_state = GIFLoadingContext::ErrorState::FailedToDecodeAnyFrame;
             return result.release_error();
         }
         m_context->error_state = GIFLoadingContext::ErrorState::FailedToDecodeAllFrames;
     }
 
-    ImageFrameDescriptor frame {};
-    frame.image = TRY(m_context->frame_buffer->clone());
-    frame.duration = m_context->images[index]->duration * 10;
+    ImageFrameDescriptor frame {
+        .image = TRY(m_context->frame_buffer->clone()),
+        .duration = m_context->images[index]->duration * 10,
+    };
 
-    if (frame.duration <= 10) {
+    if (frame.duration <= 10)
         frame.duration = 100;
-    }
 
     return frame;
 }

Libraries/LibGfx/ImageFormats/ICOLoader.cpp

@@ -171,10 +171,6 @@ ErrorOr<void> ICOImageDecoderPlugin::load_ico_bitmap(ICOLoadingContext& context)
     if (PNGImageDecoderPlugin::sniff({ context.data + desc.offset, desc.size })) {
         auto png_decoder = TRY(PNGImageDecoderPlugin::create({ context.data + desc.offset, desc.size }));
         auto decoded_png_frame = TRY(png_decoder->frame(0));
-        if (!decoded_png_frame.image) {
-            dbgln_if(ICO_DEBUG, "load_ico_bitmap: failed to load PNG encoded image index: {}", real_index);
-            return Error::from_string_literal("Encoded image not null");
-        }
         desc.bitmap = decoded_png_frame.image;
         return {};
     } else {
@@ -184,10 +180,6 @@ ErrorOr<void> ICOImageDecoderPlugin::load_ico_bitmap(ICOLoadingContext& context)
         // inside an ICO image.
         if (bmp_decoder->sniff_dib()) {
             auto decoded_bmp_frame = TRY(bmp_decoder->frame(0));
-            if (!decoded_bmp_frame.image) {
-                dbgln_if(ICO_DEBUG, "load_ico_bitmap: failed to load BMP encoded image index: {}", real_index);
-                return Error::from_string_literal("Encoded image not null");
-            }
             desc.bitmap = decoded_bmp_frame.image;
         } else {
             dbgln_if(ICO_DEBUG, "load_ico_bitmap: encoded image not supported at index: {}", real_index);
@@ -244,7 +236,7 @@ ErrorOr<ImageFrameDescriptor> ICOImageDecoderPlugin::frame(size_t index, Optiona
     }
 
     VERIFY(m_context->images[m_context->largest_index].bitmap);
-    return ImageFrameDescriptor { m_context->images[m_context->largest_index].bitmap, 0 };
+    return ImageFrameDescriptor { *m_context->images[m_context->largest_index].bitmap, 0 };
 }
 
 }

Libraries/LibGfx/ImageFormats/ImageDecoder.h

@@ -23,12 +23,12 @@ namespace Gfx {
 class Bitmap;
 
 struct ImageFrameDescriptor {
-    RefPtr<Bitmap> image;
+    NonnullRefPtr<Bitmap> image;
     int duration { 0 };
 };
 
 struct VectorImageFrameDescriptor {
-    RefPtr<VectorGraphic> image;
+    NonnullRefPtr<VectorGraphic> image;
     int duration { 0 };
 };
 

Libraries/LibGfx/ImageFormats/JPEGLoader.cpp

@@ -217,7 +217,7 @@ ErrorOr<ImageFrameDescriptor> JPEGImageDecoderPlugin::frame(size_t index, Option
         m_context->state = JPEGLoadingContext::State::Decoded;
     }
 
-    return ImageFrameDescriptor { m_context->rgb_bitmap, 0 };
+    return ImageFrameDescriptor { *m_context->rgb_bitmap, 0 };
 }
 
 Optional<Metadata const&> JPEGImageDecoderPlugin::metadata()

Libraries/LibGfx/ImageFormats/TIFFLoader.cpp

@@ -786,7 +786,7 @@ ErrorOr<ImageFrameDescriptor> TIFFImageDecoderPlugin::frame(size_t index, Option
     if (m_context->cmyk_bitmap())
         return ImageFrameDescriptor { TRY(m_context->cmyk_bitmap()->to_low_quality_rgb()), 0 };
 
-    return ImageFrameDescriptor { m_context->bitmap(), 0 };
+    return ImageFrameDescriptor { *m_context->bitmap(), 0 };
 }
 
 Optional<Metadata const&> TIFFImageDecoderPlugin::metadata()

Libraries/LibGfx/ImageFormats/TinyVGLoader.cpp

@@ -571,13 +571,13 @@ ErrorOr<ImageFrameDescriptor> TinyVGImageDecoderPlugin::frame(size_t, Optional<I
     auto target_size = ideal_size.value_or(m_context->decoded_image->size());
     if (!m_context->bitmap || m_context->bitmap->size() != target_size)
         m_context->bitmap = TRY(m_context->decoded_image->bitmap(target_size));
-    return ImageFrameDescriptor { m_context->bitmap };
+    return ImageFrameDescriptor { *m_context->bitmap };
 }
 
 ErrorOr<VectorImageFrameDescriptor> TinyVGImageDecoderPlugin::vector_frame(size_t)
 {
     TRY(ensure_fully_decoded(*m_context));
-    return VectorImageFrameDescriptor { m_context->decoded_image, 0 };
+    return VectorImageFrameDescriptor { *m_context->decoded_image, 0 };
 }
 
 }