PDFViewer: Propagate errors from OutlineModel construction

This follows the same idea that Andreas was doing in this latest videos,
where construction-time TRY()s were not present but should have been.
Like Andreas did, moving the initialisation of such fields to the
factory function, which then returns ErrorOr solves the issue.

Userland/Applications/PDFViewer/OutlineModel.cpp

@@ -7,16 +7,17 @@
 #include "OutlineModel.h"
 #include <LibGfx/Font/FontDatabase.h>
 
-NonnullRefPtr<OutlineModel> OutlineModel::create(NonnullRefPtr<PDF::OutlineDict> const& outline)
+ErrorOr<NonnullRefPtr<OutlineModel>> OutlineModel::create(NonnullRefPtr<PDF::OutlineDict> const& outline)
 {
-    return adopt_ref(*new OutlineModel(outline));
+    auto outline_model = adopt_ref(*new OutlineModel(outline));
+    outline_model->m_closed_item_icon.set_bitmap_for_size(16, TRY(Gfx::Bitmap::try_load_from_file("/res/icons/16x16/book.png"sv)));
+    outline_model->m_open_item_icon.set_bitmap_for_size(16, TRY(Gfx::Bitmap::try_load_from_file("/res/icons/16x16/book-open.png"sv)));
+    return outline_model;
 }
 
 OutlineModel::OutlineModel(NonnullRefPtr<PDF::OutlineDict> const& outline)
     : m_outline(outline)
 {
-    m_closed_item_icon.set_bitmap_for_size(16, Gfx::Bitmap::try_load_from_file("/res/icons/16x16/book.png"sv).release_value_but_fixme_should_propagate_errors());
-    m_open_item_icon.set_bitmap_for_size(16, Gfx::Bitmap::try_load_from_file("/res/icons/16x16/book-open.png"sv).release_value_but_fixme_should_propagate_errors());
 }
 
 void OutlineModel::set_index_open_state(const GUI::ModelIndex& index, bool is_open)

Userland/Applications/PDFViewer/OutlineModel.h

@@ -12,7 +12,7 @@
 
 class OutlineModel final : public GUI::Model {
 public:
-    static NonnullRefPtr<OutlineModel> create(NonnullRefPtr<PDF::OutlineDict> const& outline);
+    static ErrorOr<NonnullRefPtr<OutlineModel>> create(NonnullRefPtr<PDF::OutlineDict> const& outline);
 
     void set_index_open_state(const GUI::ModelIndex& index, bool is_open);
 

Userland/Applications/PDFViewer/PDFViewerWidget.cpp

@@ -376,11 +376,11 @@ PDF::PDFErrorOr<void> PDFViewerWidget::try_open_file(Core::File& file)
 
     if (document->outline()) {
         auto outline = document->outline();
-        m_sidebar->set_outline(outline.release_nonnull());
+        TRY(m_sidebar->set_outline(outline.release_nonnull()));
         m_sidebar->set_visible(true);
         m_sidebar_open = true;
     } else {
-        m_sidebar->set_outline({});
+        TRY(m_sidebar->set_outline({}));
         m_sidebar->set_visible(false);
         m_sidebar_open = false;
     }

Userland/Applications/PDFViewer/SidebarWidget.h

@@ -16,15 +16,16 @@ class SidebarWidget final : public GUI::Widget {
 public:
     ~SidebarWidget() override = default;
 
-    void set_outline(RefPtr<PDF::OutlineDict> outline)
+    ErrorOr<void> set_outline(RefPtr<PDF::OutlineDict> outline)
     {
         if (outline) {
-            m_model = OutlineModel::create(outline.release_nonnull());
+            m_model = TRY(OutlineModel::create(outline.release_nonnull()));
             m_outline_tree_view->set_model(m_model);
         } else {
             m_model = RefPtr<OutlineModel> {};
             m_outline_tree_view->set_model({});
         }
+        return {};
     }
 
 private: