ReadlineWindow.cc

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// **************************************************************************
// **************************************************************************
#include "Shell.h"

#include <sstream>
#include <iostream>
#include <string.h> // strlen

#include "tools.h"

using namespace std;

// --------------------------------------------------------------------------
//
ReadlineWindow::ReadlineWindow(const char *prgname) : Readline(prgname),
    fWindow(0), fPromptX(0), fPromptY(0)
{
}

// --------------------------------------------------------------------------
//
//
void ReadlineWindow::SetWindow(WINDOW *w)
{
    if (!w)
        return;

    // Get size of the window
    int width, height;
    getmaxyx(w, height, width);

    // Propagate the size to the readline library
    Resize(width, height);

    // Finally set the pointer to the panel in which we are supposed to
    // operate
    fWindow = w;
}


// --------------------------------------------------------------------------
//
//
/*
int ReadlineWindow::Getc(FILE *)
{
    //         from the continous call to event hook anyway

    // Get size of the window
    int lines, cols;
    getmaxyx(fWindow, lines, cols);

    // Get current cursor position
    int x0, y0, y1, x1;
    getyx(fWindow, y0, x0);

    // Read a character from stream in window
    const int c = wgetch(fWindow);

    // Get new cursor position
    getyx(fWindow, y1, x1);

    // Find out whether the last character initiated a scroll
    if (y0==lines-1 && y1==lines-1 && x1==0 && x0==cols-1)
        fPromptY--;

    // return character
    return c;
}
*/

// --------------------------------------------------------------------------
//
//
void ReadlineWindow::Startup()
{
    getyx(fWindow, fPromptY, fPromptX);
}

// --------------------------------------------------------------------------
//
//
void ReadlineWindow::RewindCursor() const
{
    wmove(fWindow, fPromptY, fPromptX);
}

// --------------------------------------------------------------------------
//
//
void ReadlineWindow::EventHook(bool)
{
    Readline::EventHook();
    Redisplay();
    /*
     * This doesn't work if the contents of the line changes, e.g. when
     * the prompt is replaced

    // Refresh the screen
    Refresh();

    // Now move the cursor to its expected position
    int lines, cols;
    getmaxyx(fWindow, lines, cols);

    const int pos = fPromptY*cols + fPromptX + GetAbsCursor();
    wmove(fWindow, pos/cols, pos%cols);

    // Make the cursor movement visible on the screen
    wrefresh(fWindow);
    */

    // The lines above are just a simplified version of Redisplay()
    // which skips all the output.
}

// --------------------------------------------------------------------------
//
//
void ReadlineWindow::Redisplay()
{
    // Move to the beginning of the output
    wmove(fWindow, fPromptY, fPromptX);

    // Get site of the window
    int lines, cols;
    getmaxyx(fWindow, lines, cols);

    const string prompt = GetPrompt();
    const string buffer = GetBuffer();

    // Issue promt and redisplay text
    wattron(fWindow, fColor);
    wprintw(fWindow, "%s", prompt.c_str());
    wattroff(fWindow, fColor);
    wprintw(fWindow, "%s", buffer.c_str());

    // Clear everything after that
    wclrtobot(fWindow);

    // Calculate absolute position in window or beginning of output
    int xy = fPromptY*cols + fPromptX;

    // Calculate position of end of prompt
    xy += prompt.length();

    // Calculate position of cursor and end of output
    const int cur = xy + GetCursor();
    const int end = xy + buffer.size();

    // Calculate if the above output scrolled the window and by how many lines
    int scrolls = end/cols - lines + 1;

    if (scrolls<0)
        scrolls = 0;

    fPromptY -= scrolls;

    // new position
    const int px = cur%cols;
    const int py = scrolls>=1 ? cur/cols - scrolls : cur/cols;

    // Make sure that whatever happens while typing the correct
    // screen is shown (otherwise the top-panel disappears when
    // we scroll)
    Refresh();

    // Move the cursor to the cursor position
    wmove(fWindow, py, px);

    // Make changes visible on screen
    wrefresh(fWindow);
}

// --------------------------------------------------------------------------
//
//
void ReadlineWindow::CompletionDisplay(char **matches, int num, int max)
{
    // Increase maximum size by two to get gaps in between the columns
    max += 2; // Two whitespaces in between the output

    // Get size of window
    int lines, cols;
    getmaxyx(fWindow, lines, cols);

    // Allow an empty space at the end of the lines for a '\n'
    cols--;

    // calculate the final number columns
    const int ncols = cols / max;

    // Compile a proper format string
    ostringstream fmt;
    fmt << "%-" << max << 's';

    // loop over all entries and display them
    int l=0;
    for (int i=0; i<num; i++)
    {
        // Check if we have to put a line-break
        if (i%ncols==0)
        {
            if ((max+0)*ncols < cols)
                wprintw(fWindow, "\n");
            l++;
        }

        // Display an entry
        wprintw(fWindow, fmt.str().c_str(), matches[i+1]);
    }

    // Display an empty line after the list
    if ((num-1)%ncols>0)
        wprintw(fWindow, "\n");
    wprintw(fWindow, "\n");

    // Get new cursor position
    int x, y;
    getyx(fWindow, y, x);

    // Clear everything behind the list
    wclrtobot(fWindow);

    // Adapt fPromptY for the number of scrolled lines if any.
    if (y==lines-1)
        fPromptY = lines-1;

    // Display anything
    wrefresh(fWindow);
}

// --------------------------------------------------------------------------
//
//
void ReadlineWindow::Shutdown(const char *buf)
{
    // Move the cursor to the end of the total line entered by the user
    // (the user might have pressed return in the middle of the line)...
    int lines, cols;
    getmaxyx(fWindow, lines, cols);

    // Calculate absolute position in window or beginning of output
    // We can't take a pointer to the buffer because rl_end is not
    // valid anymore at the end of a readline call
    int xy = fPromptY*cols + fPromptX + GetPrompt().size() + strlen(buf);
    wmove(fWindow, xy/cols, xy%cols);

    // ...and output a newline. We have to do the manually.
    wprintw(fWindow, "\n");

    // refresh the screen
    wrefresh(fWindow);

    // This might have scrolled the window
    if (xy/cols==lines-1)
        fPromptY--;
}