couple more fixes

[lyx.git] / src / lyxlength.C

diff --git a/src/lyxlength.C b/src/lyxlength.C
index b9586b1c3bb5ef88d4ff211ae8d5bef251eb9a55..2e16c84ed3ea28f122cd381397dfbcd31f59d159 100644 (file)
--- a/src/lyxlength.C
+++ b/src/lyxlength.C
@@ -53,7 +53,7 @@ string const LyXLength::asString() const
 {
        ostringstream buffer;
        buffer << val_ << unit_name[unit_]; // setw?
-       return buffer.str().c_str();
+       return STRCONV(buffer.str());
 }
 
 
@@ -89,7 +89,7 @@ string const LyXLength::asLatexString() const
            buffer << val_ << unit_name[unit_]; // setw?
            break;
        }
-       return buffer.str().c_str();
+       return STRCONV(buffer.str());
 }
 
 
@@ -123,7 +123,7 @@ bool LyXLength::zero() const
 }
 
 
-int LyXLength::inPixels(int default_width, int default_height) const
+int LyXLength::inPixels(int text_width, int em_width_base) const
 {
        // Zoom factor specified by user in percent
        double const zoom = lyxrc.zoom / 100.0; // [percent]
@@ -131,18 +131,23 @@ int LyXLength::inPixels(int default_width, int default_height) const
        // DPI setting for monitor: pixels/inch
        double const dpi = lyxrc.dpi; // screen resolution [pixels/inch]
 
+       double const em_width = (em_width_base > 0)
+               ? em_width_base
+               : 10*(dpi/72.27)*zoom;
+       // A different estimate for em_width is
+       // font_metrics::width('M', LyXFont(LyXFont::ALL_SANE))
+       // but this estimate might not be more accurate as the screen font
+       // is different then the latex font.
+
        // Pixel values are scaled so that the ratio
        // between lengths and font sizes on the screen
        // is the same as on paper.
 
-       // we don't care about sign of value, we
-       // display negative space with text too
 #ifdef WITH_WARNINGS
 #warning if you don't care than either call this function differently or let it return negative values and call abs() explicitly when needed (Andre')
 #endif
 
        double result = 0.0;
-       int val_sign = val_ < 0.0 ? -1 : 1;
 
        switch (unit_) {
        case LyXLength::SP:
@@ -191,31 +196,37 @@ int LyXLength::inPixels(int default_width, int default_height) const
                break;
        case LyXLength::EX:
                // Ex: The height of an "x"
-               result = zoom * val_ * default_height / 2; // what to / width?
+               // 0.4305 is the ration between 1ex and 1em in cmr10
+               result = val_ * em_width * 0.4305;
                break;
-       case LyXLength::EM: // what to / width?
+       case LyXLength::EM:
                // Em: The width of an "m"
-               result = zoom * val_ * default_height / 2; // Why 2?
+               result = val_ * em_width;
                break;
-       case LyXLength::MU: // This is probably only allowed in
-               // math mode
-               result = zoom * val_ * default_height;
+       case LyXLength::MU:
+               // math unit = 1/18em
+               result = val_ * em_width / 18;
                break;
        case LyXLength::PCW: // Always % of workarea
        case LyXLength::PTW:
-       case LyXLength::PPW:
        case LyXLength::PLW:
-               result = val_ * default_width / 100;
+               result = val_ * text_width / 100;
+               break;
+       case LyXLength::PPW:
+               // paperwidth/textwidth is 1.7 for A4 paper with default margins
+               result = val_ * text_width * 1.7 / 100;
                break;
        case LyXLength::PTH:
+               result = val_ * text_width * 1.787 / 100;
+               break;
        case LyXLength::PPH:
-               result = val_ * default_height / 100;
+               result = val_ * text_width * 2.2 / 100;
                break;
        case LyXLength::UNIT_NONE:
                result = 0;  // this cannot happen
                break;
        }
-       return static_cast<int>(result * val_sign + 0.5);
+       return static_cast<int>(result + ((result >= 0) ? 0.5 : -0.5));
 }