Spreadsheet: Reorganise the sources a bit

This commit just moves some code around:
- Give Cell its own file
- Pull all forward-declared classes/structs into Forward.h
- Clean up the order of member functions a bit

8 files changed, 250 insertions, 146 deletions

diff --git a/Applications/Spreadsheet/CMakeLists.txt b/Applications/Spreadsheet/CMakeLists.txt
index 9eac41dc0f..5ec5efee9a 100644
--- a/Applications/Spreadsheet/CMakeLists.txt
+++ b/Applications/Spreadsheet/CMakeLists.txt
@@ -1,4 +1,5 @@
 set(SOURCES
+    Cell.cpp
     CellSyntaxHighlighter.cpp
     HelpWindow.cpp
     JSIntegration.cpp
diff --git a/Applications/Spreadsheet/Cell.cpp b/Applications/Spreadsheet/Cell.cpp
new file mode 100644
index 0000000000..d44d02debf
--- /dev/null
+++ b/Applications/Spreadsheet/Cell.cpp
@@ -0,0 +1,120 @@
+/*
+ * Copyright (c) 2020, the SerenityOS developers.
+ * 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.
+ */
+
+#include "Cell.h"
+#include "Spreadsheet.h"
+#include <AK/StringBuilder.h>
+
+namespace Spreadsheet {
+
+void Cell::set_data(String new_data)
+{
+    if (data == new_data)
+        return;
+
+    if (new_data.starts_with("=")) {
+        new_data = new_data.substring(1, new_data.length() - 1);
+        kind = Formula;
+    } else {
+        kind = LiteralString;
+    }
+
+    data = move(new_data);
+    dirty = true;
+    evaluated_externally = false;
+}
+
+void Cell::set_data(JS::Value new_data)
+{
+    dirty = true;
+    evaluated_externally = true;
+
+    StringBuilder builder;
+
+    builder.append(new_data.to_string_without_side_effects());
+    data = builder.build();
+
+    evaluated_data = move(new_data);
+}
+
+void Cell::update_data()
+{
+    TemporaryChange cell_change { sheet->current_evaluated_cell(), this };
+    if (!dirty)
+        return;
+
+    dirty = false;
+    if (kind == Formula) {
+        if (!evaluated_externally)
+            evaluated_data = sheet->evaluate(data, this);
+    }
+
+    for (auto& ref : referencing_cells) {
+        if (ref) {
+            ref->dirty = true;
+            ref->update();
+        }
+    }
+}
+
+void Cell::update()
+{
+    sheet->update(*this);
+}
+
+JS::Value Cell::js_data()
+{
+    if (dirty)
+        update();
+
+    if (kind == Formula)
+        return evaluated_data;
+
+    return JS::js_string(sheet->interpreter(), data);
+}
+
+String Cell::source() const
+{
+    StringBuilder builder;
+    if (kind == Formula)
+        builder.append('=');
+    builder.append(data);
+    return builder.to_string();
+}
+
+// FIXME: Find a better way to figure out dependencies
+void Cell::reference_from(Cell* other)
+{
+    if (!other || other == this)
+        return;
+
+    if (!referencing_cells.find([other](auto& ptr) { return ptr.ptr() == other; }).is_end())
+        return;
+
+    referencing_cells.append(other->make_weak_ptr());
+}
+
+}
diff --git a/Applications/Spreadsheet/Cell.h b/Applications/Spreadsheet/Cell.h
new file mode 100644
index 0000000000..6fed58f4b9
--- /dev/null
+++ b/Applications/Spreadsheet/Cell.h
@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2020, the SerenityOS developers.
+ * 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 "Forward.h"
+#include "JSIntegration.h"
+#include <AK/String.h>
+#include <AK/Types.h>
+#include <AK/WeakPtr.h>
+
+namespace Spreadsheet {
+
+struct Cell : public Weakable<Cell> {
+    Cell(String data, WeakPtr<Sheet> sheet)
+        : dirty(false)
+        , data(move(data))
+        , kind(LiteralString)
+        , sheet(sheet)
+    {
+    }
+
+    Cell(String source, JS::Value&& cell_value, WeakPtr<Sheet> sheet)
+        : dirty(false)
+        , data(move(source))
+        , evaluated_data(move(cell_value))
+        , kind(Formula)
+        , sheet(sheet)
+    {
+    }
+
+    void reference_from(Cell*);
+
+    void set_data(String new_data);
+    void set_data(JS::Value new_data);
+
+    String source() const;
+
+    JS::Value js_data();
+
+    void update(Badge<Sheet>) { update_data(); }
+    void update();
+
+    enum Kind {
+        LiteralString,
+        Formula,
+    };
+
+    bool dirty { false };
+    bool evaluated_externally { false };
+    String data;
+    JS::Value evaluated_data;
+    Kind kind { LiteralString };
+    WeakPtr<Sheet> sheet;
+    Vector<WeakPtr<Cell>> referencing_cells;
+
+private:
+    void update_data();
+};
+
+}
diff --git a/Applications/Spreadsheet/Forward.h b/Applications/Spreadsheet/Forward.h
new file mode 100644
index 0000000000..5bd5480025
--- /dev/null
+++ b/Applications/Spreadsheet/Forward.h
@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2020, the SerenityOS developers.
+ * 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
+
+namespace Spreadsheet {
+
+struct Cell;
+class Sheet;
+struct Position;
+class Workbook;
+class WorkbookObject;
+class SheetGlobalObject;
+
+}
diff --git a/Applications/Spreadsheet/JSIntegration.h b/Applications/Spreadsheet/JSIntegration.h
index bd3bd1e77f..ace3e3c823 100644
--- a/Applications/Spreadsheet/JSIntegration.h
+++ b/Applications/Spreadsheet/JSIntegration.h
@@ -26,14 +26,12 @@
 
 #pragma once
 
+#include "Forward.h"
 #include <LibJS/Forward.h>
 #include <LibJS/Runtime/GlobalObject.h>
 
 namespace Spreadsheet {
 
-class Sheet;
-class Workbook;
-
 class SheetGlobalObject : public JS::GlobalObject {
     JS_OBJECT(SheetGlobalObject, JS::GlobalObject);
 
diff --git a/Applications/Spreadsheet/Spreadsheet.cpp b/Applications/Spreadsheet/Spreadsheet.cpp
index de8410d06d..fb250d177e 100644
--- a/Applications/Spreadsheet/Spreadsheet.cpp
+++ b/Applications/Spreadsheet/Spreadsheet.cpp
@@ -77,16 +77,15 @@ Sheet::Sheet(Workbook& workbook)
             }
         }
     }
-
 }
 
-JS::Interpreter& Sheet::interpreter() const
+Sheet::~Sheet()
 {
-    return m_workbook.interpreter();
 }
 
-Sheet::~Sheet()
+JS::Interpreter& Sheet::interpreter() const
 {
+    return m_workbook.interpreter();
 }
 
 size_t Sheet::add_row()
@@ -171,42 +170,6 @@ JS::Value Sheet::evaluate(const StringView& source, Cell* on_behalf_of)
     return value;
 }
 
-void Cell::update_data()
-{
-    TemporaryChange cell_change { sheet->current_evaluated_cell(), this };
-    if (!dirty)
-        return;
-
-    dirty = false;
-    if (kind == Formula) {
-        if (!evaluated_externally)
-            evaluated_data = sheet->evaluate(data, this);
-    }
-
-    for (auto& ref : referencing_cells) {
-        if (ref) {
-            ref->dirty = true;
-            ref->update();
-        }
-    }
-}
-
-void Cell::update()
-{
-    sheet->update(*this);
-}
-
-JS::Value Cell::js_data()
-{
-    if (dirty)
-        update();
-
-    if (kind == Formula)
-        return evaluated_data;
-
-    return JS::js_string(sheet->interpreter(), data);
-}
-
 Cell* Sheet::at(const StringView& name)
 {
     auto pos = parse_cell_name(name);
@@ -238,27 +201,6 @@ Optional<Position> Sheet::parse_cell_name(const StringView& name)
     return Position { col, row.to_uint().value() };
 }
 
-String Cell::source() const
-{
-    StringBuilder builder;
-    if (kind == Formula)
-        builder.append('=');
-    builder.append(data);
-    return builder.to_string();
-}
-
-// FIXME: Find a better way to figure out dependencies
-void Cell::reference_from(Cell* other)
-{
-    if (!other || other == this)
-        return;
-
-    if (!referencing_cells.find([other](auto& ptr) { return ptr.ptr() == other; }).is_end())
-        return;
-
-    referencing_cells.append(other->make_weak_ptr());
-}
-
 RefPtr<Sheet> Sheet::from_json(const JsonObject& object, Workbook& workbook)
 {
     auto sheet = adopt(*new Sheet(workbook));
diff --git a/Applications/Spreadsheet/Spreadsheet.h b/Applications/Spreadsheet/Spreadsheet.h
index c711624ce4..3207398ec8 100644
--- a/Applications/Spreadsheet/Spreadsheet.h
+++ b/Applications/Spreadsheet/Spreadsheet.h
@@ -26,6 +26,8 @@
 
 #pragma once
 
+#include "Cell.h"
+#include "Forward.h"
 #include <AK/HashMap.h>
 #include <AK/HashTable.h>
 #include <AK/String.h>
@@ -39,9 +41,6 @@
 
 namespace Spreadsheet {
 
-class Workbook;
-class SheetGlobalObject;
-
 struct Position {
     String column;
     size_t row { 0 };
@@ -57,83 +56,6 @@ struct Position {
     }
 };
 
-class Sheet;
-
-struct Cell : public Weakable<Cell> {
-    Cell(String data, WeakPtr<Sheet> sheet)
-        : dirty(false)
-        , data(move(data))
-        , kind(LiteralString)
-        , sheet(sheet)
-    {
-    }
-
-    Cell(String source, JS::Value&& cell_value, WeakPtr<Sheet> sheet)
-        : dirty(false)
-        , data(move(source))
-        , evaluated_data(move(cell_value))
-        , kind(Formula)
-        , sheet(sheet)
-    {
-    }
-
-    bool dirty { false };
-    bool evaluated_externally { false };
-    String data;
-    JS::Value evaluated_data;
-
-    enum Kind {
-        LiteralString,
-        Formula,
-    } kind { LiteralString };
-
-    WeakPtr<Sheet> sheet;
-    Vector<WeakPtr<Cell>> referencing_cells;
-
-    void reference_from(Cell*);
-
-    void set_data(String new_data)
-    {
-        if (data == new_data)
-            return;
-
-        if (new_data.starts_with("=")) {
-            new_data = new_data.substring(1, new_data.length() - 1);
-            kind = Formula;
-        } else {
-            kind = LiteralString;
-        }
-
-        data = move(new_data);
-        dirty = true;
-        evaluated_externally = false;
-    }
-
-    void set_data(JS::Value new_data)
-    {
-        dirty = true;
-        evaluated_externally = true;
-
-        StringBuilder builder;
-
-        builder.append("=");
-        builder.append(new_data.to_string_without_side_effects());
-        data = builder.build();
-
-        evaluated_data = move(new_data);
-    }
-
-    String source() const;
-
-    JS::Value js_data();
-
-    void update(Badge<Sheet>) { update_data(); }
-    void update();
-
-private:
-    void update_data();
-};
-
 class Sheet : public Core::Object {
     C_OBJECT(Sheet);
 
diff --git a/Applications/Spreadsheet/Workbook.h b/Applications/Spreadsheet/Workbook.h
index 54295fbe67..7c31db1f31 100644
--- a/Applications/Spreadsheet/Workbook.h
+++ b/Applications/Spreadsheet/Workbook.h
@@ -26,14 +26,13 @@
 
 #pragma once
 
+#include "Forward.h"
 #include "Spreadsheet.h"
 #include <AK/NonnullOwnPtrVector.h>
 #include <AK/Result.h>
 
 namespace Spreadsheet {
 
-class WorkbookObject;
-
 class Workbook {
 public:
     Workbook(NonnullRefPtrVector<Sheet>&& sheets);