LibGUI: Add GJsonArrayModel, a simple JSON-data-file-as-GModel helper

This makes it very easy to expose JSON files as GModels. :^)

Libraries/LibGUI/GJsonArrayModel.cpp

@@ -0,0 +1,41 @@
+#include <AK/JsonObject.h>
+#include <LibCore/CFile.h>
+#include <LibGUI/GJsonArrayModel.h>
+
+void GJsonArrayModel::update()
+{
+    CFile file(m_json_path);
+    if (!file.open(CIODevice::ReadOnly)) {
+        dbg() << "Unable to open " << file.filename();
+        return;
+    }
+
+    auto json = JsonValue::from_string(file.read_all());
+
+    ASSERT(json.is_array());
+    m_array = json.as_array();
+
+    did_update();
+}
+
+GModel::ColumnMetadata GJsonArrayModel::column_metadata(int column) const
+{
+    ASSERT(column < m_fields.size());
+    return { 100, m_fields[column].text_alignment };
+}
+
+GVariant GJsonArrayModel::data(const GModelIndex& index, Role role) const
+{
+    auto& object = m_array.at(index.row()).as_object();
+
+    if (role == GModel::Role::Display) {
+        auto& json_field_name = m_fields[index.column()].json_field_name;
+        auto data = object.get(json_field_name);
+        if (data.is_int())
+            return data.as_int();
+        if (data.is_uint())
+            return data.as_uint();
+        return object.get(json_field_name).to_string();
+    }
+    return {};
+}

Libraries/LibGUI/GJsonArrayModel.h

@@ -0,0 +1,38 @@
+#pragma once
+
+#include <AK/JsonArray.h>
+#include <LibGUI/GModel.h>
+
+class GJsonArrayModel final : public GModel {
+public:
+    struct FieldSpec {
+        String json_field_name;
+        String column_name;
+        TextAlignment text_alignment;
+    };
+
+    static NonnullRefPtr<GJsonArrayModel> create(const String& json_path, Vector<FieldSpec>&& fields)
+    {
+        return adopt(*new GJsonArrayModel(json_path, move(fields)));
+    }
+
+    virtual ~GJsonArrayModel() override {}
+
+    virtual int row_count(const GModelIndex& = GModelIndex()) const override { return m_array.size(); }
+    virtual int column_count(const GModelIndex& = GModelIndex()) const override { return m_fields.size(); }
+    virtual String column_name(int column) const override { return m_fields[column].column_name; }
+    virtual ColumnMetadata column_metadata(int) const override;
+    virtual GVariant data(const GModelIndex&, Role = Role::Display) const override;
+    virtual void update() override;
+
+private:
+    GJsonArrayModel(const String& json_path, Vector<FieldSpec>&& fields)
+        : m_json_path(json_path)
+        , m_fields(move(fields))
+    {
+    }
+
+    String m_json_path;
+    Vector<FieldSpec> m_fields;
+    JsonArray m_array;
+};

Libraries/LibGUI/Makefile

@@ -52,6 +52,7 @@ OBJS = \
     GAbstractButton.o \
     GListView.o \
     GComboBox.o \
+    GJsonArrayModel.o \
     GWindow.o
 
 LIBRARY = libgui.a