Extract document resize planning

src/app_core/document_resize.h

@@ -0,0 +1,57 @@
+#pragma once
+
+#include "app_core/app_status.h"
+#include "foundation/result.h"
+
+#include <string>
+#include <string_view>
+
+namespace pp::app {
+
+struct DocumentResizeDialogState {
+    int current_resolution = 0;
+    std::string current_resolution_text;
+    int current_resolution_index = 0;
+};
+
+struct DocumentResizePlan {
+    int resolution = 0;
+    int width = 0;
+    int height = 0;
+    bool clears_history = false;
+};
+
+[[nodiscard]] inline DocumentResizeDialogState make_document_resize_dialog_state(
+    int current_resolution)
+{
+    const auto label = document_resolution_label(current_resolution);
+    const auto index = document_resolution_to_index(current_resolution);
+    std::string text = "Current: ";
+    text.append(label ? std::string_view(label.value()) : std::string_view("unknown"));
+
+    return {
+        current_resolution,
+        text,
+        index ? static_cast<int>(index.value()) : static_cast<int>(document_resolution_values.size()),
+    };
+}
+
+[[nodiscard]] inline pp::foundation::Result<DocumentResizePlan> plan_document_resize(
+    int selected_resolution_index)
+{
+    const auto resolution = display_resolution_from_index(selected_resolution_index);
+    if (!resolution) {
+        return pp::foundation::Result<DocumentResizePlan>::failure(resolution.status());
+    }
+
+    const auto value = resolution.value();
+    return pp::foundation::Result<DocumentResizePlan>::success(
+        DocumentResizePlan {
+            value,
+            value,
+            value,
+            true,
+        });
+}
+
+}