Units: make it absolutely clear that Document properties unit dropdown is for UI Display Units. Upon document load, calculate the units used for SVG values, if a viewbox is available. If not, default to "px" SVG units.

Change all code to use either Display units OR svg units.

(bzr r13751)

2 files changed, 27 insertions, 0 deletions

diff --git a/src/util/units.cpp b/src/util/units.cpp
index 3d635e2d2..8ad3560dd 100644
--- a/src/util/units.cpp
+++ b/src/util/units.cpp
@@ -21,6 +21,8 @@
 #include <glibmm/fileutils.h>
 #include <glibmm/markup.h>
 
+#include <2geom/coord.h>
+
 #include "util/units.h"
 #include "path-prefix.h"
 #include "streq.h"
@@ -279,6 +281,28 @@ Unit const *UnitTable::getUnit(SVGLength::Unit u) const
     return &_empty_unit;
 }
 
+Unit const *UnitTable::findUnit(double factor, UnitType type) const
+{
+    const double eps = factor * 0.01; // allow for 1% deviation
+
+    UnitCodeMap::const_iterator cit = _unit_map.begin();
+    while (cit != _unit_map.end()) {
+        if (cit->second->type == type) {
+            if (Geom::are_near(cit->second->factor, factor, eps)) {
+                // unit found!
+                break;
+            }
+        }
+        ++cit;
+    }
+
+    if (cit != _unit_map.end()) {
+        return cit->second;
+    } else {
+        return getUnit(_primary_unit[type]);
+    }
+}
+
 Quantity UnitTable::parseQuantity(Glib::ustring const &q) const
 {
     Glib::MatchInfo match_info;
diff --git a/src/util/units.h b/src/util/units.h
index efe1dbec7..13777fd1b 100644
--- a/src/util/units.h
+++ b/src/util/units.h
@@ -141,6 +141,9 @@ public:
     /** Retrieve a given unit based on its string identifier */
     Unit const *getUnit(Glib::ustring const &name) const;
     Unit const *getUnit(char const *name) const;
+
+    /** Try to find a unit based on its conversion factor to the primary */
+    Unit const *findUnit(double factor, UnitType type) const;
     
     /** Retrieve a given unit based on its SVGLength unit */
     Unit const *getUnit(SVGLength::Unit u) const;