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			127 lines
		
	
	
	
		
			2.4 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			127 lines
		
	
	
	
		
			2.4 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
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|  * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
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|  *
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|  * SPDX-License-Identifier: BSD-2-Clause
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|  */
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| 
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| #include <LibGUI/Command.h>
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| #include <LibGUI/UndoStack.h>
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| 
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| namespace GUI {
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| 
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| UndoStack::UndoStack()
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| {
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| }
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| 
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| UndoStack::~UndoStack()
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| {
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| }
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| 
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| bool UndoStack::can_undo() const
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| {
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|     return m_stack_index > 0;
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| }
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| 
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| bool UndoStack::can_redo() const
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| {
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|     if (m_stack.is_empty())
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|         return false;
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|     return m_stack_index != m_stack.size();
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| }
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| 
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| void UndoStack::undo()
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| {
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|     if (!can_undo())
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|         return;
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| 
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|     auto& command = m_stack[--m_stack_index];
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|     command.undo();
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| 
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|     if (on_state_change)
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|         on_state_change();
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| }
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| 
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| void UndoStack::redo()
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| {
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|     if (!can_redo())
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|         return;
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| 
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|     auto& command = m_stack[m_stack_index++];
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|     command.redo();
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| 
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|     if (on_state_change)
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|         on_state_change();
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| }
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| 
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| void UndoStack::push(NonnullOwnPtr<Command> command)
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| {
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|     // If the stack cursor is behind the top of the stack, nuke everything from here to the top.
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|     while (m_stack.size() != m_stack_index)
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|         (void)m_stack.take_last();
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| 
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|     if (m_clean_index.has_value() && m_clean_index.value() > m_stack.size())
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|         m_clean_index = {};
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| 
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|     if (!m_stack.is_empty() && is_current_modified()) {
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|         if (m_stack.last().merge_with(*command))
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|             return;
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|     }
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| 
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|     m_stack.append(move(command));
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|     m_stack_index = m_stack.size();
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| 
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|     if (on_state_change)
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|         on_state_change();
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| }
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| 
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| void UndoStack::set_current_unmodified()
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| {
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|     if (m_clean_index.has_value() && m_clean_index.value() == m_stack_index)
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|         return;
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| 
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|     m_clean_index = m_stack_index;
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|     m_last_unmodified_timestamp = Time::now_monotonic();
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| 
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|     if (on_state_change)
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|         on_state_change();
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| }
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| 
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| bool UndoStack::is_current_modified() const
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| {
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|     if (m_stack.is_empty())
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|         return false;
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|     if (!m_clean_index.has_value())
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|         return true;
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|     if (m_stack_index != m_clean_index.value())
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|         return true;
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|     return false;
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| }
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| 
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| void UndoStack::clear()
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| {
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|     if (m_stack.is_empty() && m_stack_index == 0 && !m_clean_index.has_value())
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|         return;
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| 
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|     m_stack.clear();
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|     m_stack_index = 0;
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|     m_clean_index.clear();
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| 
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|     if (on_state_change)
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|         on_state_change();
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| }
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| 
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| Optional<String> UndoStack::undo_action_text() const
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| {
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|     if (!can_undo())
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|         return {};
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|     return m_stack[m_stack_index - 1].action_text();
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| }
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| 
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| Optional<String> UndoStack::redo_action_text() const
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| {
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|     if (!can_redo())
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|         return {};
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|     return m_stack[m_stack_index].action_text();
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| }
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| 
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| }
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