From c2c0d6f04236d7a993974a47e3762649cc0b25c9 Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Sun, 25 Sep 2016 23:01:59 -0400
Subject: [PATCH] add a piece table insertion test

---
 src/core/PieceTable.cc | 72 ++++++++++++++++++++++++++++++++++++++++++
 src/core/PieceTable.h  |  4 +++
 src/gui/Window.cc      |  9 ++++++
 src/gui/Window.h       |  1 +
 4 files changed, 86 insertions(+)

diff --git a/src/core/PieceTable.cc b/src/core/PieceTable.cc
index cb4fb4f..062fd98 100644
--- a/src/core/PieceTable.cc
+++ b/src/core/PieceTable.cc
@@ -10,6 +10,7 @@ PieceTable::PieceTable(const uint8_t * file_buffer, unsigned long file_buffer_si
     end_piece->prev = start_piece;
     m_piece_index = 2u;
     tabstop = 4u;
+    m_append_buffer_index = 0u;
 }
 
 void PieceTable::append_initial_line_piece(uint8_t * start, uint32_t length, bool eol)
@@ -240,6 +241,14 @@ bool PieceTable::Cursor::go_right(int n)
     return true;
 }
 
+void PieceTable::Cursor::warp_to_inserted_piece(Piece * piece)
+{
+    iterator.piece = piece;
+    iterator.offset = 0u;
+    iterator.go_end_of_piece();
+    calculate_column();
+}
+
 bool PieceTable::Cursor::is_start_of_line()
 {
     return iterator.valid() &&
@@ -323,3 +332,66 @@ void PieceTable::Cursor::forward_to_column(uint32_t c)
         diff = new_diff;
     }
 }
+
+void PieceTable::insertion_test(Cursor & c)
+{
+    Piece * piece = add_piece();
+    piece->start = &m_append_buffer[m_append_buffer_index];
+    piece->length = 3u;
+    piece->flags = 0u;
+    m_append_buffer[m_append_buffer_index++] = 'x';
+    m_append_buffer[m_append_buffer_index++] = 'y';
+    m_append_buffer[m_append_buffer_index++] = 'z';
+    if (c.iterator.valid())
+    {
+        if (c.iterator.offset > 0u)
+        {
+            Piece * piece2 = add_piece();
+            piece2->start = c.iterator.piece->start;
+            piece2->length = c.iterator.offset;
+            piece2->flags = 0u;
+
+            Piece * piece3 = add_piece();
+            piece3->start = c.iterator.piece->start + c.iterator.offset;
+            piece3->length = c.iterator.piece->length - c.iterator.offset;
+            piece3->flags = c.iterator.piece->flags;
+
+            c.iterator.piece->prev->next = piece2;
+            piece2->prev = c.iterator.piece->prev;
+            piece2->next = piece;
+            piece->prev = piece2;
+
+            piece->next = piece3;
+            piece3->prev = piece;
+            piece3->next = c.iterator.piece->next;
+            piece3->next->prev = piece3;
+        }
+        else
+        {
+            if (c.iterator.piece->length == 0u)
+            {
+                piece->flags = c.iterator.piece->flags;
+                c.iterator.piece->prev->next = piece;
+                c.iterator.piece->next->prev = piece;
+                piece->prev = c.iterator.piece->prev;
+                piece->next = c.iterator.piece->next;
+            }
+            else
+            {
+                c.iterator.piece->prev->next = piece;
+                piece->prev = c.iterator.piece->prev;
+                c.iterator.piece->prev = piece;
+                piece->next = c.iterator.piece;
+            }
+        }
+    }
+    else
+    {
+        start_piece->next = piece;
+        piece->prev = start_piece;
+        end_piece->prev = piece;
+        piece->next = end_piece;
+    }
+
+    c.warp_to_inserted_piece(piece);
+}
diff --git a/src/core/PieceTable.h b/src/core/PieceTable.h
index d84d93d..8dbdbd2 100644
--- a/src/core/PieceTable.h
+++ b/src/core/PieceTable.h
@@ -120,6 +120,7 @@ public:
         {
             return (c.line == line) && (c.column == column);
         }
+        void warp_to_inserted_piece(Piece * piece);
 
     protected:
         bool is_start_of_line();
@@ -154,6 +155,8 @@ public:
 
     std::shared_ptr<Cursor> add_cursor();
 
+    void insertion_test(Cursor & c);
+
 protected:
     const uint8_t * m_file_buffer;
     unsigned long m_file_buffer_size;
@@ -163,6 +166,7 @@ protected:
     uint32_t m_piece_index;
 
     PagedBuffer<uint8_t> m_append_buffer;
+    uint32_t m_append_buffer_index;
     PagedBuffer<Piece> m_pieces;
 
     std::list<std::shared_ptr<Cursor>> m_cursors;
diff --git a/src/gui/Window.cc b/src/gui/Window.cc
index 5c7ac78..0f2e043 100644
--- a/src/gui/Window.cc
+++ b/src/gui/Window.cc
@@ -268,6 +268,9 @@ void Window::handle_key(uint32_t scancode, uint32_t mod)
     case SDL_SCANCODE_L:
         cursor_move(CURSOR_RIGHT);
         break;
+    case SDL_SCANCODE_P:
+        insertion_test();
+        break;
     }
 }
 
@@ -521,3 +524,9 @@ void Window::draw_status_bar()
         x += m_font.get_advance();
     }
 }
+
+void Window::insertion_test()
+{
+    m_buffer->piece_table->insertion_test(*m_cursor);
+    redraw();
+}
diff --git a/src/gui/Window.h b/src/gui/Window.h
index 7bea24e..44eb172 100644
--- a/src/gui/Window.h
+++ b/src/gui/Window.h
@@ -42,6 +42,7 @@ protected:
     void update_cursor_row(int cursor_row);
     void draw_rect(int x, int y, int width, int height, float r, float g, float b, float a);
     void draw_status_bar();
+    void insertion_test();
 
     SDL_Window * m_window;
     bool m_exit_requested;