Libraries: Move to Userland/Libraries/

1 files changed, 103 insertions, 0 deletions

diff --git a/Userland/Libraries/LibGUI/UndoStack.cpp b/Userland/Libraries/LibGUI/UndoStack.cpp
new file mode 100644
index 0000000000..775997ef47
--- /dev/null
+++ b/Userland/Libraries/LibGUI/UndoStack.cpp
@@ -0,0 +1,103 @@
+/*
+ * 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.
+ */
+
+#include <LibGUI/Command.h>
+#include <LibGUI/UndoStack.h>
+
+namespace GUI {
+
+UndoStack::UndoStack()
+{
+}
+
+UndoStack::~UndoStack()
+{
+}
+
+void UndoStack::undo()
+{
+    if (!can_undo())
+        return;
+
+    auto pop_container_and_undo = [this]() {
+        for (;;) {
+            if (m_stack_index >= m_stack.size())
+                break;
+
+            auto& container = m_stack[m_stack_index++];
+            if (container.m_undo_vector.size() == 0)
+                continue;
+            for (auto& command : container.m_undo_vector)
+                command.undo();
+            break;
+        }
+    };
+
+    // If this is the first undo, finish off our current combo
+    if (m_stack_index == 0)
+        finalize_current_combo();
+    pop_container_and_undo();
+}
+
+void UndoStack::redo()
+{
+    if (!can_redo())
+        return;
+
+    m_stack_index -= 1;
+    auto& vector = m_stack[m_stack_index].m_undo_vector;
+    for (int i = vector.size() - 1; i >= 0; i--)
+        vector[i].redo();
+}
+
+void UndoStack::push(NonnullOwnPtr<Command>&& command)
+{
+    if (m_stack.is_empty())
+        finalize_current_combo();
+
+    if (m_stack_index > 0) {
+        for (size_t i = 0; i < m_stack_index; i++)
+            m_stack.remove(0);
+        m_stack_index = 0;
+        finalize_current_combo();
+    }
+
+    auto& current_vector = m_stack.first().m_undo_vector;
+    current_vector.prepend(move(command));
+}
+
+void UndoStack::finalize_current_combo()
+{
+    if (m_stack_index > 0)
+        return;
+    if (m_stack.size() != 0 && m_stack.first().m_undo_vector.size() == 0)
+        return;
+
+    auto undo_commands_container = make<UndoCommandsContainer>();
+    m_stack.prepend(move(undo_commands_container));
+}
+
+}