Reflow when executing an app

The reflow need to guess where the cursor line is when the user change
the konsole window size while executing an app.

src/Screen.cpp

@@ -383,6 +383,36 @@ bool Screen::isResize()
     return _isResize;
 }
 
+// Not to production auxiliar functions to show what is written in screen or history
+void toDebug(const Character s[], int count, bool wrapped = false) {
+    QString out;
+    for (int i = 0; i < count; i++) {
+        out += s[i].character;
+    }
+    qDebug() << out << (wrapped? " wrapped" : "");
+}
+void toDebug(const QVector<Character> &s, bool wrapped = false) {
+    toDebug(s.data(), s.size(), wrapped);
+}
+/////
+
+int Screen::getCursorLine()
+{
+    if (_currentModes[MODE_AppScreen] == 1) {
+        return _savedState.cursorLine;
+    }
+    return _cuY;
+}
+
+void Screen::setCursorLine(int newLine)
+{
+    if (_currentModes[MODE_AppScreen] == 1) {
+        _savedState.cursorLine = newLine;
+    } else {
+        _cuY = newLine;
+    }
+}
+
 void Screen::resizeImage(int new_lines, int new_columns)
 {
     if ((new_lines == _lines) && (new_columns == _columns)) {
@@ -393,41 +423,47 @@ void Screen::resizeImage(int new_lines, int new_columns)
     _oldTotalLines = getLines() + getHistLines();
     _isResize = true;
 
+    int cursorLine = getCursorLine();
+    const int oldCursorLine = (cursorLine == _lines -1)? new_lines - 1 : cursorLine;
+
     // First join everything.
     int currentPos = 0;
-    if (new_columns != _columns) {
-        while (currentPos < _cuY && currentPos < _screenLines.count() - 1) {
-            // if the line have the 'LINE_WRAPPED' property, concat with the next line and remove it.
-            if ((_lineProperties[currentPos] & LINE_WRAPPED) != 0) {
-                _screenLines[currentPos].append(_screenLines[currentPos + 1]);
-                _screenLines.remove(currentPos + 1);
-                _lineProperties.remove(currentPos);
-                _cuY--;
-                continue;
-            }
-            currentPos++;
+    while (currentPos < cursorLine && currentPos < _screenLines.count() - 1) {
+        // if the line have the 'LINE_WRAPPED' property, concat with the next line and remove it.
+        if ((_lineProperties[currentPos] & LINE_WRAPPED) != 0) {
+            _screenLines[currentPos].append(_screenLines[currentPos + 1]);
+            _screenLines.remove(currentPos + 1);
+            _lineProperties.remove(currentPos);
+            cursorLine--;
+            continue;
         }
-        // Then move the data to lines below.
-        currentPos = 0;
-        while (currentPos != _screenLines.count() && currentPos != _cuY) {
-            const bool shouldCopy = _screenLines[currentPos].size() > new_columns;
-
-            // Copy from the current line, to the next one.
-            if (shouldCopy) {
-                _cuY++;
-
-                auto values = _screenLines[currentPos].mid(new_columns);
-                _screenLines[currentPos].remove(new_columns, values.size());
-                _lineProperties.insert(currentPos + 1, _lineProperties[currentPos]);
-                _screenLines.insert(currentPos + 1, values);
-                _lineProperties[currentPos] |= LINE_WRAPPED;
-            }
-            currentPos += 1;
+        currentPos++;
+    }
+    // Then move the data to lines below.
+    currentPos = 0;
+    while (currentPos < cursorLine && currentPos < _screenLines.count()) {
+        // Ignore whitespaces at the end of the line
+        int lineSize = _screenLines[currentPos].size();
+        while (lineSize > 0 && QChar(_screenLines[currentPos][lineSize - 1].character).isSpace()) {
+            lineSize--;
+        }
+        const bool shouldCopy = lineSize > new_columns;
+
+        // Copy from the current line, to the next one.
+        if (shouldCopy) {
+            auto values = _screenLines[currentPos].mid(new_columns);
+            _screenLines[currentPos].remove(new_columns, values.size());
+            _lineProperties.insert(currentPos + 1, _lineProperties[currentPos]);
+            _screenLines.insert(currentPos + 1, values);
+            _lineProperties[currentPos] |= LINE_WRAPPED;
+            cursorLine++;
         }
+        currentPos += 1;
     }
     // Check if it need to move from _screenLine to _history
-    while (_cuY > new_lines - 1) {
+    while (cursorLine > new_lines - 1) {
         fastAddHistLine();
+        cursorLine--;
     }
     _lineProperties.resize(new_lines + 1);
     _screenLines.resize(new_lines + 1);
@@ -437,6 +473,7 @@ void Screen::resizeImage(int new_lines, int new_columns)
         // Join next line from _screenLine to _history
         while (_history->isWrappedLine(_history->getLines() - 1)) {
             fastAddHistLine();
+            cursorLine--;
         }
         currentPos = 0;
         // Join everything in _history
@@ -494,7 +531,7 @@ void Screen::resizeImage(int new_lines, int new_columns)
     // Check cursor position and send from _history to _screenLines
     ImageLine histLine;
     histLine.reserve(1024);
-    while (_cuY < new_lines - 1 && _history->getLines()) {
+    while (cursorLine < oldCursorLine && _history->getLines()) {
         int histPos = _history->getLines() - 1;
         int histLineLen = _history->getLineLen(histPos);
         int isWrapped = _history->isWrappedLine(histPos)? LINE_WRAPPED : LINE_DEFAULT;
@@ -503,7 +540,7 @@ void Screen::resizeImage(int new_lines, int new_columns)
         _screenLines.insert(0, histLine);
         _lineProperties.insert(0, isWrapped);
         _history->removeCells(histPos);
-        _cuY++;
+        cursorLine++;
     }
 
     _lineProperties.resize(new_lines + 1);
@@ -516,7 +553,8 @@ void Screen::resizeImage(int new_lines, int new_columns)
     _lines = new_lines;
     _columns = new_columns;
     _cuX = qMin(_cuX, _columns - 1);
-    _cuY = qMin(_cuY, _lines - 1);
+    cursorLine = qBound(0, cursorLine, _lines - 1);
+    setCursorLine(cursorLine);
 
     // FIXME: try to keep values, evtl.
     setDefaultMargins();
@@ -1571,7 +1609,7 @@ void Screen::writeLinesToStream(TerminalCharacterDecoder* decoder, int fromLine,
 
 void Screen::fastAddHistLine()
 {
-    bool removeLine = _history->getLines() == _history->getMaxLines();
+    const bool removeLine = _history->getLines() == _history->getMaxLines();
     _history->addCellsVector(_screenLines[0]);
     _history->addLine((_lineProperties[0] & LINE_WRAPPED) != 0);
 
@@ -1583,7 +1621,6 @@ void Screen::fastAddHistLine()
 
     _screenLines.pop_front();
     _lineProperties.remove(0);
-    _cuY--;
 }
 
 void Screen::addHistLine()

src/Screen.h

@@ -25,7 +25,8 @@
 #define MODE_Screen    3
 #define MODE_Cursor    4
 #define MODE_NewLine   5
-#define MODES_SCREEN   6
+#define MODE_AppScreen 6
+#define MODES_SCREEN   7
 
 namespace Konsole {
 class TerminalCharacterDecoder;
@@ -653,6 +654,11 @@ private:
     // should be as minimal as possible
     static Character *getCharacterBuffer(const int size);
 
+    // Get the cursor line after checking if its app mode or not
+    int getCursorLine();
+    // Set the cursor line after checking if its app mode or not
+    void setCursorLine (int newLine);
+
     int getLineLength(const int line) const;
 
     // screen image ----------------

src/Vt102Emulation.cpp

@@ -1464,8 +1464,8 @@ void Vt102Emulation::resetMode(int m)
         setScreen(0);
         break;
     }
-    // FIXME: Currently this has a redundant condition as MODES_SCREEN is 6
-    // and MODE_NewLine is 5
+    // FIXME: Currently this has a redundant condition as MODES_SCREEN is 7
+    // MODE_AppScreen is 6 and MODE_NewLine is 5
     if (m < MODES_SCREEN || m == MODE_NewLine) {
         _screen[0]->resetMode(m);
         _screen[1]->resetMode(m);

src/Vt102Emulation.h

@@ -20,22 +20,21 @@
 class QTimer;
 class QKeyEvent;
 
-#define MODE_AppScreen       (MODES_SCREEN+0)   // Mode #1
-#define MODE_AppCuKeys       (MODES_SCREEN+1)   // Application cursor keys (DECCKM)
-#define MODE_AppKeyPad       (MODES_SCREEN+2)   //
-#define MODE_Mouse1000       (MODES_SCREEN+3)   // Send mouse X,Y position on press and release
-#define MODE_Mouse1001       (MODES_SCREEN+4)   // Use Hilight mouse tracking
-#define MODE_Mouse1002       (MODES_SCREEN+5)   // Use cell motion mouse tracking
-#define MODE_Mouse1003       (MODES_SCREEN+6)   // Use all motion mouse tracking
-#define MODE_Mouse1005       (MODES_SCREEN+7)   // Xterm-style extended coordinates
-#define MODE_Mouse1006       (MODES_SCREEN+8)   // 2nd Xterm-style extended coordinates
-#define MODE_Mouse1007       (MODES_SCREEN+9)   // XTerm Alternate Scroll mode; also check AlternateScrolling profile property
-#define MODE_Mouse1015       (MODES_SCREEN+10)   // Urxvt-style extended coordinates
-#define MODE_Ansi            (MODES_SCREEN+11)   // Use US Ascii for character sets G0-G3 (DECANM)
-#define MODE_132Columns      (MODES_SCREEN+12)  // 80 <-> 132 column mode switch (DECCOLM)
-#define MODE_Allow132Columns (MODES_SCREEN+13)  // Allow DECCOLM mode
-#define MODE_BracketedPaste  (MODES_SCREEN+14)  // Xterm-style bracketed paste mode
-#define MODE_total           (MODES_SCREEN+15)
+#define MODE_AppCuKeys       (MODES_SCREEN+0)   // Application cursor keys (DECCKM)
+#define MODE_AppKeyPad       (MODES_SCREEN+1)   //
+#define MODE_Mouse1000       (MODES_SCREEN+2)   // Send mouse X,Y position on press and release
+#define MODE_Mouse1001       (MODES_SCREEN+3)   // Use Hilight mouse tracking
+#define MODE_Mouse1002       (MODES_SCREEN+4)   // Use cell motion mouse tracking
+#define MODE_Mouse1003       (MODES_SCREEN+5)   // Use all motion mouse tracking
+#define MODE_Mouse1005       (MODES_SCREEN+6)   // Xterm-style extended coordinates
+#define MODE_Mouse1006       (MODES_SCREEN+7)   // 2nd Xterm-style extended coordinates
+#define MODE_Mouse1007       (MODES_SCREEN+8)   // XTerm Alternate Scroll mode; also check AlternateScrolling profile property
+#define MODE_Mouse1015       (MODES_SCREEN+9)   // Urxvt-style extended coordinates
+#define MODE_Ansi            (MODES_SCREEN+10)   // Use US Ascii for character sets G0-G3 (DECANM)
+#define MODE_132Columns      (MODES_SCREEN+11)  // 80 <-> 132 column mode switch (DECCOLM)
+#define MODE_Allow132Columns (MODES_SCREEN+12)  // Allow DECCOLM mode
+#define MODE_BracketedPaste  (MODES_SCREEN+13)  // Xterm-style bracketed paste mode
+#define MODE_total           (MODES_SCREEN+14)
 
 namespace Konsole {
 extern unsigned short vt100_graphics[32];