more code in the menu backend == less code in the menu frontends; add support for...

[lyx.git] / src / lyxlength.C

diff --git a/src/lyxlength.C b/src/lyxlength.C
index b9586b1c3bb5ef88d4ff211ae8d5bef251eb9a55..c38e7a33729300a0e59ae5ecafa17f3faedb16a1 100644 (file)
--- a/src/lyxlength.C
+++ b/src/lyxlength.C
@@ -10,10 +10,6 @@
 
 #include <config.h>
 
-#ifdef __GNUG__
-#pragma implementation
-#endif
-
 #include "lyxlength.h"
 #include "lengthcommon.h"
 #include "lyxrc.h"
@@ -27,7 +23,7 @@
 using std::abs;
 
 LyXLength::LyXLength()
-       : val_(0), unit_(LyXLength::PT)
+       : val_(0), unit_(LyXLength::UNIT_NONE)
 {}
 
 
@@ -53,7 +49,7 @@ string const LyXLength::asString() const
 {
        ostringstream buffer;
        buffer << val_ << unit_name[unit_]; // setw?
-       return buffer.str().c_str();
+       return STRCONV(buffer.str());
 }
 
 
@@ -62,34 +58,34 @@ string const LyXLength::asLatexString() const
        ostringstream buffer;
        switch (unit_) {
        case PTW:
-           buffer << abs(static_cast<int>(val_/100)) << "."
+           buffer << abs(static_cast<int>(val_/100)) << '.'
                   << abs(static_cast<int>(val_)%100) << "\\textwidth";
            break;
        case PCW:
-           buffer << abs(static_cast<int>(val_/100)) << "."
+           buffer << abs(static_cast<int>(val_/100)) << '.'
                   << abs(static_cast<int>(val_)%100) << "\\columnwidth";
            break;
        case PPW:
-           buffer << abs(static_cast<int>(val_/100)) << "."
+           buffer << abs(static_cast<int>(val_/100)) << '.'
                   << abs(static_cast<int>(val_)%100) << "\\paperwidth";
            break;
        case PLW:
-           buffer << abs(static_cast<int>(val_/100)) << "."
+           buffer << abs(static_cast<int>(val_/100)) << '.'
                   << abs(static_cast<int>(val_)%100) << "\\linewidth";
            break;
        case PPH:
-           buffer << abs(static_cast<int>(val_/100)) << "."
+           buffer << abs(static_cast<int>(val_/100)) << '.'
                   << abs(static_cast<int>(val_)%100) << "\\paperheight";
            break;
        case PTH:
-           buffer << abs(static_cast<int>(val_/100)) << "."
+           buffer << abs(static_cast<int>(val_/100)) << '.'
                   << abs(static_cast<int>(val_)%100) << "\\textheight";
            break;
        default:
            buffer << val_ << unit_name[unit_]; // setw?
            break;
        }
-       return buffer.str().c_str();
+       return STRCONV(buffer.str());
 }
 
 
@@ -123,7 +119,13 @@ bool LyXLength::zero() const
 }
 
 
-int LyXLength::inPixels(int default_width, int default_height) const
+bool LyXLength::empty() const
+{
+       return unit_ == LyXLength::UNIT_NONE;
+}
+
+
+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 +133,23 @@ 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 +198,37 @@ 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));
 }