+++ /dev/null
-// Copyright (c) 2015 Ryan Prichard
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to
-// deal in the Software without restriction, including without limitation the
-// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
-// sell copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
-// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
-// IN THE SOFTWARE.
-
-//
-// ConsoleLine
-//
-// This data structure keep tracks of the previous CHAR_INFO content of an
-// output line and determines when a line has changed. Detecting line changes
-// is made complicated by terminal resizing.
-//
-
-#include "ConsoleLine.h"
-
-#include <algorithm>
-
-#include "../shared/WinptyAssert.h"
-
-static CHAR_INFO blankChar(WORD attributes)
-{
- // N.B.: As long as we write to UnicodeChar rather than AsciiChar, there
- // are no padding bytes that could contain uninitialized bytes. This fact
- // is important for efficient comparison.
- CHAR_INFO ret;
- ret.Attributes = attributes;
- ret.Char.UnicodeChar = L' ';
- return ret;
-}
-
-static bool isLineBlank(const CHAR_INFO *line, int length, WORD attributes)
-{
- for (int col = 0; col < length; ++col) {
- if (line[col].Attributes != attributes ||
- line[col].Char.UnicodeChar != L' ') {
- return false;
- }
- }
- return true;
-}
-
-static inline bool areLinesEqual(
- const CHAR_INFO *line1,
- const CHAR_INFO *line2,
- int length)
-{
- return memcmp(line1, line2, sizeof(CHAR_INFO) * length) == 0;
-}
-
-ConsoleLine::ConsoleLine() : m_prevLength(0)
-{
-}
-
-void ConsoleLine::reset()
-{
- m_prevLength = 0;
- m_prevData.clear();
-}
-
-// Determines whether the given line is sufficiently different from the
-// previously seen line as to justify reoutputting the line. The function
-// also sets the `ConsoleLine` to the given line, exactly as if `setLine` had
-// been called.
-bool ConsoleLine::detectChangeAndSetLine(const CHAR_INFO *const line, const int newLength)
-{
- ASSERT(newLength >= 1);
- ASSERT(m_prevLength <= static_cast<int>(m_prevData.size()));
-
- if (newLength == m_prevLength) {
- bool equalLines = areLinesEqual(m_prevData.data(), line, newLength);
- if (!equalLines) {
- setLine(line, newLength);
- }
- return !equalLines;
- } else {
- if (m_prevLength == 0) {
- setLine(line, newLength);
- return true;
- }
-
- ASSERT(m_prevLength >= 1);
- const WORD prevBlank = m_prevData[m_prevLength - 1].Attributes;
- const WORD newBlank = line[newLength - 1].Attributes;
-
- bool equalLines = false;
- if (newLength < m_prevLength) {
- // The line has become shorter. The lines are equal if the common
- // part is equal, and if the newly truncated characters were blank.
- equalLines =
- areLinesEqual(m_prevData.data(), line, newLength) &&
- isLineBlank(m_prevData.data() + newLength,
- m_prevLength - newLength,
- newBlank);
- } else {
- //
- // The line has become longer. The lines are equal if the common
- // part is equal, and if both the extra characters and any
- // potentially reexposed characters are blank.
- //
- // Two of the most relevant terminals for winpty--mintty and
- // jediterm--don't (currently) erase the obscured content when a
- // line is cleared, so we should anticipate its existence when
- // making a terminal wider and reoutput the line. See:
- //
- // * https://github.com/mintty/mintty/issues/480
- // * https://github.com/JetBrains/jediterm/issues/118
- //
- ASSERT(newLength > m_prevLength);
- equalLines =
- areLinesEqual(m_prevData.data(), line, m_prevLength) &&
- isLineBlank(m_prevData.data() + m_prevLength,
- std::min<int>(m_prevData.size(), newLength) - m_prevLength,
- prevBlank) &&
- isLineBlank(line + m_prevLength,
- newLength - m_prevLength,
- prevBlank);
- }
- setLine(line, newLength);
- return !equalLines;
- }
-}
-
-void ConsoleLine::setLine(const CHAR_INFO *const line, const int newLength)
-{
- if (static_cast<int>(m_prevData.size()) < newLength) {
- m_prevData.resize(newLength);
- }
- memcpy(m_prevData.data(), line, sizeof(CHAR_INFO) * newLength);
- m_prevLength = newLength;
-}
-
-void ConsoleLine::blank(WORD attributes)
-{
- m_prevData.resize(1);
- m_prevData[0] = blankChar(attributes);
- m_prevLength = 1;
-}
projects / VSoRC / .git / blobdiff