1 files changed, 132 insertions, 0 deletions
diff --git a/Userland/Libraries/LibGUI/Model.h b/Userland/Libraries/LibGUI/Model.h
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+++ b/Userland/Libraries/LibGUI/Model.h
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+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <AK/Badge.h>
+#include <AK/Function.h>
+#include <AK/HashTable.h>
+#include <AK/RefCounted.h>
+#include <AK/String.h>
+#include <LibCore/MimeData.h>
+#include <LibGUI/ModelIndex.h>
+#include <LibGUI/ModelRole.h>
+#include <LibGUI/ModelSelection.h>
+#include <LibGUI/Variant.h>
+#include <LibGfx/Forward.h>
+#include <LibGfx/TextAlignment.h>
+
+namespace GUI {
+
+enum class SortOrder {
+    None,
+    Ascending,
+    Descending
+};
+
+class ModelClient {
+public:
+    virtual ~ModelClient() { }
+
+    virtual void model_did_update(unsigned flags) = 0;
+};
+
+class Model : public RefCounted<Model> {
+public:
+    enum UpdateFlag {
+        DontInvalidateIndexes = 0,
+        InvalidateAllIndexes = 1 << 0,
+    };
+
+    enum MatchesFlag {
+        AllMatching = 0,
+        FirstMatchOnly = 1 << 0,
+        CaseInsensitive = 1 << 1,
+        MatchAtStart = 1 << 2,
+    };
+
+    virtual ~Model();
+
+    virtual int row_count(const ModelIndex& = ModelIndex()) const = 0;
+    virtual int column_count(const ModelIndex& = ModelIndex()) const = 0;
+    virtual String column_name(int) const { return {}; }
+    virtual Variant data(const ModelIndex&, ModelRole = ModelRole::Display) const = 0;
+    virtual TriState data_matches(const ModelIndex&, Variant) const { return TriState::Unknown; }
+    virtual void update() = 0;
+    virtual ModelIndex parent_index(const ModelIndex&) const { return {}; }
+    virtual ModelIndex index(int row, int column = 0, const ModelIndex& parent = ModelIndex()) const;
+    virtual bool is_editable(const ModelIndex&) const { return false; }
+    virtual bool is_searchable() const { return false; }
+    virtual void set_data(const ModelIndex&, const Variant&) { }
+    virtual int tree_column() const { return 0; }
+    virtual bool accepts_drag(const ModelIndex&, const Vector<String>& mime_types) const;
+    virtual Vector<ModelIndex, 1> matches(const StringView&, unsigned = MatchesFlag::AllMatching, const ModelIndex& = ModelIndex()) { return {}; }
+
+    virtual bool is_column_sortable([[maybe_unused]] int column_index) const { return true; }
+    virtual void sort([[maybe_unused]] int column, SortOrder) { }
+
+    bool is_valid(const ModelIndex& index) const
+    {
+        auto parent_index = this->parent_index(index);
+        return index.row() >= 0 && index.row() < row_count(parent_index) && index.column() >= 0 && index.column() < column_count(parent_index);
+    }
+
+    virtual StringView drag_data_type() const { return {}; }
+    virtual RefPtr<Core::MimeData> mime_data(const ModelSelection&) const;
+
+    void register_view(Badge<AbstractView>, AbstractView&);
+    void unregister_view(Badge<AbstractView>, AbstractView&);
+
+    void register_client(ModelClient&);
+    void unregister_client(ModelClient&);
+
+protected:
+    Model();
+
+    void for_each_view(Function<void(AbstractView&)>);
+    void did_update(unsigned flags = UpdateFlag::InvalidateAllIndexes);
+
+    static bool string_matches(const StringView& str, const StringView& needle, unsigned flags)
+    {
+        auto case_sensitivity = (flags & CaseInsensitive) ? CaseSensitivity::CaseInsensitive : CaseSensitivity::CaseSensitive;
+        if (flags & MatchAtStart)
+            return str.starts_with(needle, case_sensitivity);
+        return str.contains(needle, case_sensitivity);
+    }
+
+    ModelIndex create_index(int row, int column, const void* data = nullptr) const;
+
+private:
+    HashTable<AbstractView*> m_views;
+    HashTable<ModelClient*> m_clients;
+};
+
+inline ModelIndex ModelIndex::parent() const
+{
+    return m_model ? m_model->parent_index(*this) : ModelIndex();
+}
+
+}