Moterm part 1: Add MotermModel, a "model" for terminal emulation.

apps/moterm/moterm_model.cc

Index: apps/moterm/moterm_model.cc
diff --git a/apps/moterm/moterm_model.cc b/apps/moterm/moterm_model.cc
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index 0000000000000000000000000000000000000000..3b321585b0ab52c10b02cff8cd3330168190b514
--- /dev/null
+++ b/apps/moterm/moterm_model.cc
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+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "apps/moterm/moterm_model.h"
+
+#include <string.h>
+
+#include <algorithm>
+#include <limits>
+
+#include "base/logging.h"
+
+namespace {
+
+// Moterm -> teken conversions:
+
+teken_pos_t MotermToTekenSize(const MotermModel::Size& size) {
+  DCHECK_LE(size.rows, std::numeric_limits<teken_unit_t>::max());
+  DCHECK_LE(size.columns, std::numeric_limits<teken_unit_t>::max());
+  teken_pos_t rv = {static_cast<teken_unit_t>(size.rows),
+                    static_cast<teken_unit_t>(size.columns)};
+  return rv;
+}
+
+// Teken -> moterm conversions:
+
+MotermModel::Position TekenToMotermPosition(const teken_pos_t& position) {
+  return MotermModel::Position(static_cast<int>(position.tp_row),
+                               static_cast<int>(position.tp_col));
+}
+
+MotermModel::Size TekenToMotermSize(const teken_pos_t& size) {
+  return MotermModel::Size(size.tp_row, size.tp_col);
+}
+
+MotermModel::Rectangle TekenToMotermRectangle(const teken_rect_t& rectangle) {
+  return MotermModel::Rectangle(
+      static_cast<int>(rectangle.tr_begin.tp_row),
+      static_cast<int>(rectangle.tr_begin.tp_col),
+      rectangle.tr_end.tp_row - rectangle.tr_begin.tp_row,
+      rectangle.tr_end.tp_col - rectangle.tr_begin.tp_col);
+}
+
+MotermModel::Color TekenToMotermColor(teken_color_t color, bool bold) {
+  static const uint8_t rgb[TC_NCOLORS][3] = {
+      {0x00, 0x00, 0x00},  // Black.
+      {0x80, 0x00, 0x00},  // Red.
+      {0x00, 0x80, 0x00},  // Green.
+      {0x80, 0x80, 0x00},  // Yellow (even if teken thinks it's brown).
+      {0x00, 0x00, 0x80},  // Blue.
+      {0x80, 0x00, 0x80},  // Magenta.
+      {0x00, 0x80, 0x80},  // Cyan.
+      {0xc0, 0xc0, 0xc0}   // White.
+  };
+  static const uint8_t bold_rgb[TC_NCOLORS][3] = {
+      {0x80, 0x80, 0x80},  // Black.
+      {0xff, 0x00, 0x00},  // Red.
+      {0x00, 0xff, 0x00},  // Green.
+      {0xff, 0xff, 0x00},  // Yellow (even if teken thinks it's brown).
+      {0x00, 0x00, 0xff},  // Blue.
+      {0xff, 0x00, 0xff},  // Magenta.
+      {0x00, 0xff, 0xff},  // Cyan.
+      {0xff, 0xff, 0xff}   // White.
+  };
+  DCHECK_LT(color, static_cast<unsigned>(TC_NCOLORS));
+  return bold ? MotermModel::Color(bold_rgb[color][0], bold_rgb[color][1],
+                                   bold_rgb[color][2])
+              : MotermModel::Color(rgb[color][0], rgb[color][1], rgb[color][2]);
+}
+
+// Utility functions:
+
+MotermModel::Rectangle EnclosingRectangle(const MotermModel::Rectangle& rect1,
+                                          const MotermModel::Rectangle& rect2) {
+  if (rect1.IsEmpty())
+    return rect2;
+  if (rect2.IsEmpty())
+    return rect1;
+
+  int start_row = std::min(rect1.position.row, rect2.position.row);
+  int start_col = std::min(rect1.position.column, rect2.position.column);
+  // TODO(vtl): Some theoretical overflows here.
+  int end_row =
+      std::max(rect1.position.row + static_cast<int>(rect1.size.rows),
+               rect2.position.row + static_cast<int>(rect2.size.rows));
+  int end_col =
+      std::max(rect1.position.column + static_cast<int>(rect1.size.columns),
+               rect2.position.column + static_cast<int>(rect2.size.columns));
+  DCHECK_LE(start_row, end_row);
+  DCHECK_LE(start_col, end_col);
+  return MotermModel::Rectangle(start_row, start_col,
+                                static_cast<unsigned>(end_row - start_row),
+                                static_cast<unsigned>(end_col - start_col));
+}
+
+}  // namespace
+
+const MotermModel::Attributes MotermModel::kAttributesBold;
+const MotermModel::Attributes MotermModel::kAttributesUnderline;
+const MotermModel::Attributes MotermModel::kAttributesBlink;
+
+const unsigned MotermModel::kMaxRows;
+const unsigned MotermModel::kMaxColumns;
+
+MotermModel::MotermModel(const Size& max_size, const Size& size)
+    : max_size_(max_size), terminal_(), current_state_changes_() {
+  DCHECK_GT(max_size_.rows, 0u);
+  DCHECK_LE(max_size_.rows, kMaxRows);
+  DCHECK_GT(max_size_.columns, 0u);
+  DCHECK_LE(max_size_.columns, kMaxColumns);
+
+  DCHECK_GT(size.rows, 0u);
+  DCHECK_LE(size.rows, max_size_.rows);
+  DCHECK_GT(size.columns, 0u);
+  DCHECK_LE(size.columns, max_size_.columns);
+
+  size_t num_chars = max_size_.rows * max_size_.columns;
+  characters_.reset(new teken_char_t[num_chars]);
+  memset(characters_.get(), 0, num_chars * sizeof(characters_[0]));
+  attributes_.reset(new teken_attr_t[num_chars]);
+  memset(attributes_.get(), 0, num_chars * sizeof(attributes_[0]));
+
+  static const teken_funcs_t callbacks = {&MotermModel::OnBellThunk,
+                                          &MotermModel::OnCursorThunk,
+                                          &MotermModel::OnPutcharThunk,
+                                          &MotermModel::OnFillThunk,
+                                          &MotermModel::OnCopyThunk,
+                                          &MotermModel::OnParamThunk,
+                                          &MotermModel::OnRespondThunk};
+  teken_init(&terminal_, &callbacks, this);
+
+  teken_pos_t s = MotermToTekenSize(size);
+  teken_set_winsize(&terminal_, &s);
+}
+
+MotermModel::~MotermModel() {
+}
+
+void MotermModel::ProcessInput(const void* input_bytes,
+                               size_t num_input_bytes,
+                               StateChanges* state_changes) {
+  DCHECK(state_changes);
+  DCHECK(!current_state_changes_);
+  current_state_changes_ = state_changes;
+
+  // Get the initial cursor position, so we'll be able to tell if it moved.
+  teken_pos_t initial_cursor_pos = *teken_get_cursor(&terminal_);
+
+  // Note: This may call some of our callbacks.
+  teken_input(&terminal_, input_bytes, num_input_bytes);
+
+  teken_pos_t final_cursor_pos = *teken_get_cursor(&terminal_);
+  if (initial_cursor_pos.tp_row != final_cursor_pos.tp_row ||
+      initial_cursor_pos.tp_col != final_cursor_pos.tp_col) {
+    state_changes->cursor_moved = true;
+    // Update dirty rect to include old and new cursor positions.
+    current_state_changes_->dirty_rect = EnclosingRectangle(
+        current_state_changes_->dirty_rect,
+        Rectangle(initial_cursor_pos.tp_row, initial_cursor_pos.tp_col, 1, 1));
+    current_state_changes_->dirty_rect = EnclosingRectangle(
+        current_state_changes_->dirty_rect,
+        Rectangle(final_cursor_pos.tp_row, final_cursor_pos.tp_col, 1, 1));
+  }
+
+  current_state_changes_ = nullptr;
+}
+
+MotermModel::Size MotermModel::GetSize() const {
+  // Teken isn't const-correct, sadly.
+  return TekenToMotermSize(
+      *teken_get_winsize(const_cast<teken_t*>(&terminal_)));
+}
+
+MotermModel::Position MotermModel::GetCursorPosition() const {
+  // Teken isn't const-correct, sadly.
+  return TekenToMotermPosition(
+      *teken_get_cursor(const_cast<teken_t*>(&terminal_)));
+}
+
+MotermModel::CharacterInfo MotermModel::GetCharacterInfoAt(
+    const Position& position) const {
+  DCHECK_GE(position.row, 0);
+  DCHECK_LT(position.row, static_cast<int>(GetSize().rows));
+  DCHECK_GE(position.column, 0);
+  DCHECK_LT(position.column, static_cast<int>(GetSize().columns));
+
+  uint32_t ch = characters_[position.row * max_size_.columns + position.column];
+  const teken_attr_t& teken_attr =
+      attributes_[position.row * max_size_.columns + position.column];
+  Color fg = TekenToMotermColor(teken_attr.ta_fgcolor,
+                                (teken_attr.ta_format & TF_BOLD));
+  Color bg = TekenToMotermColor(teken_attr.ta_bgcolor, false);
+  Attributes attr = 0;
+  if ((teken_attr.ta_format & TF_BOLD))
+    attr |= kAttributesBold;
+  if ((teken_attr.ta_format & TF_UNDERLINE))
+    attr |= kAttributesUnderline;
+  if ((teken_attr.ta_format & TF_BLINK))
+    attr |= kAttributesBlink;
+  if ((teken_attr.ta_format & TF_REVERSE))
+    std::swap(fg, bg);
+  return CharacterInfo(ch, attr, fg, bg);
+}
+
+void MotermModel::SetSize(const Size& size, bool reset) {
+  DCHECK_GT(size.rows, 1u);
+  DCHECK_LE(size.rows, max_size_.rows);
+  DCHECK_GT(size.columns, 1u);
+  DCHECK_LE(size.columns, max_size_.columns);
+  teken_pos_t teken_size = {static_cast<teken_unit_t>(size.rows),
+                            static_cast<teken_unit_t>(size.columns)};
+  if (reset) {
+    teken_set_winsize_noreset(&terminal_, &teken_size);
+  } else {
+    // We'll try a bit harder to keep a sensible cursor position.
+    teken_pos_t cursor_pos =
+        *teken_get_cursor(const_cast<teken_t*>(&terminal_));
+    teken_set_winsize(&terminal_, &teken_size);
+    if (cursor_pos.tp_row >= teken_size.tp_row)
+      cursor_pos.tp_row = teken_size.tp_row - 1;
+    if (cursor_pos.tp_col >= teken_size.tp_col)
+      cursor_pos.tp_col = teken_size.tp_col - 1;
+    teken_set_cursor(&terminal_, &cursor_pos);
+  }
+}
+
+void MotermModel::OnBell() {
+  DCHECK(current_state_changes_);
+  current_state_changes_->bell_count++;
+}
+
+void MotermModel::OnCursor(const teken_pos_t* pos) {
+  DCHECK(current_state_changes_);
+  // Don't do anything. We'll just compare initial and final cursor positions.
+}
+
+void MotermModel::OnPutchar(const teken_pos_t* pos,
+                            teken_char_t ch,
+                            const teken_attr_t* attr) {
+  character_at(pos->tp_row, pos->tp_col) = ch;
+  attribute_at(pos->tp_row, pos->tp_col) = *attr;
+
+  // Update dirty rect.
+  DCHECK(current_state_changes_);
+  current_state_changes_->dirty_rect =
+      EnclosingRectangle(current_state_changes_->dirty_rect,
+                         Rectangle(pos->tp_row, pos->tp_col, 1, 1));
+}
+
+void MotermModel::OnFill(const teken_rect_t* rect,
+                         teken_char_t ch,
+                         const teken_attr_t* attr) {
+  for (size_t row = rect->tr_begin.tp_row; row < rect->tr_end.tp_row; row++) {
+    for (size_t col = rect->tr_begin.tp_col; col < rect->tr_end.tp_col; col++) {
+      character_at(row, col) = ch;
+      attribute_at(row, col) = *attr;
+    }
+  }
+
+  // Update dirty rect.
+  DCHECK(current_state_changes_);
+  current_state_changes_->dirty_rect = EnclosingRectangle(
+      current_state_changes_->dirty_rect, TekenToMotermRectangle(*rect));
+}
+
+void MotermModel::OnCopy(const teken_rect_t* rect, const teken_pos_t* pos) {
+  unsigned height = rect->tr_end.tp_row - rect->tr_begin.tp_row;
+  unsigned width = rect->tr_end.tp_col - rect->tr_begin.tp_col;
+
+  // This is really a "move" (like |memmove()|) -- overlaps are likely. Process
+  // the rows depending on which way (vertically) we're moving.
+  if (pos->tp_row <= rect->tr_begin.tp_row) {
+    // Start from the top row.
+    for (unsigned row = 0; row < height; row++) {
+      // Use |memmove()| here, to in case we're not moving vertically.
+      memmove(&character_at(pos->tp_row + row, pos->tp_col),
+              &character_at(rect->tr_begin.tp_row + row, pos->tp_col),
+              width * sizeof(characters_[0]));
+      memmove(&attribute_at(pos->tp_row + row, pos->tp_col),
+              &attribute_at(rect->tr_begin.tp_row + row, pos->tp_col),
+              width * sizeof(attributes_[0]));
+    }
+  } else {
+    // Start from the bottom row.
+    for (unsigned row = height; row > 0;) {
+      row--;
+      // We can use |memcpy()| here.
+      memcpy(&character_at(pos->tp_row + row, pos->tp_col),
+             &character_at(rect->tr_begin.tp_row + row, pos->tp_col),
+             width * sizeof(characters_[0]));
+      memcpy(&attribute_at(pos->tp_row + row, pos->tp_col),
+             &attribute_at(rect->tr_begin.tp_row + row, pos->tp_col),
+             width * sizeof(attributes_[0]));
+    }
+  }
+
+  // Update dirty rect.
+  DCHECK(current_state_changes_);
+  current_state_changes_->dirty_rect = EnclosingRectangle(
+      current_state_changes_->dirty_rect,
+      Rectangle(static_cast<int>(pos->tp_row), static_cast<int>(pos->tp_col),
+                width, height));
+}
+
+void MotermModel::OnParam(int cmd, unsigned val) {
+  // TODO(vtl)
+  NOTIMPLEMENTED();
+}
+
+void MotermModel::OnRespond(const void* buf, size_t size) {
+  // TODO(vtl)
+  NOTIMPLEMENTED();
+}
+
+// static
+void MotermModel::OnBellThunk(void* ctx) {
+  DCHECK(ctx);
+  return static_cast<MotermModel*>(ctx)->OnBell();
+}
+
+// static
+void MotermModel::OnCursorThunk(void* ctx, const teken_pos_t* pos) {
+  DCHECK(ctx);
+  return static_cast<MotermModel*>(ctx)->OnCursor(pos);
+}
+
+// static
+void MotermModel::OnPutcharThunk(void* ctx,
+                                 const teken_pos_t* pos,
+                                 teken_char_t ch,
+                                 const teken_attr_t* attr) {
+  DCHECK(ctx);
+  return static_cast<MotermModel*>(ctx)->OnPutchar(pos, ch, attr);
+}
+
+// static
+void MotermModel::OnFillThunk(void* ctx,
+                              const teken_rect_t* rect,
+                              teken_char_t ch,
+                              const teken_attr_t* attr) {
+  DCHECK(ctx);
+  return static_cast<MotermModel*>(ctx)->OnFill(rect, ch, attr);
+}
+
+// static
+void MotermModel::OnCopyThunk(void* ctx,
+                              const teken_rect_t* rect,
+                              const teken_pos_t* pos) {
+  DCHECK(ctx);
+  return static_cast<MotermModel*>(ctx)->OnCopy(rect, pos);
+}
+
+// static
+void MotermModel::OnParamThunk(void* ctx, int cmd, unsigned val) {
+  DCHECK(ctx);
+  return static_cast<MotermModel*>(ctx)->OnParam(cmd, val);
+}
+
+// static
+void MotermModel::OnRespondThunk(void* ctx, const void* buf, size_t size) {
+  DCHECK(ctx);
+  return static_cast<MotermModel*>(ctx)->OnRespond(buf, size);
+}