Add printf style formatting to numbers in labels.

The syntax is, for example [INDEX:First (X1)]{%.3E}
Kst-plot · Dec 12, 2016 · cd764ef · cd764ef
1 parent 1de1542
commit cd764ef
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Showing 5 changed files with 73 additions and 9 deletions.
diff --git a/pyKst/pykst.py b/pyKst/pykst.py
@@ -2514,12 +2514,20 @@ class Label(ViewItem) :
   
   Scalars and scalar equations can be displayed live in labels. 
   When the scalar is updated, the label is updated.
-  
+
+
   The format is::
-    Scalar:         [scalarname]         eg [GYRO1:Mean(X4)]
-    Vector Element: [vectorName[index]]  eg [GYRO1 (V2)[4]]
-    Equation:       [=equation]          eg [=[GYRO1:Mean(X4)]/[GYRO1:Sigma (X4)]]
+
+      Scalar:         [scalarname]         eg [GYRO1:Mean(X4)]
+      Vector Element: [vectorName[index]]  eg [GYRO1 (V2)[4]]
+      Equation:       [=equation]          eg [=[GYRO1:Mean(X4)]/[GYRO1:Sigma (X4)]]
     
+
+  These numerical fields can be formatted by appending a C printf format embedded
+  in { } immediately after the field. For example::
+
+      [GYRO1:Mean(X4)]{%4.2f}
+
   Labels in kst support a derrivitive subset of LaTeX. For example, to display 
   the equation for the area of a circle, you could set the label to ``A=2\pir^2``. 
   Unlike LaTeX, it is not necessary to enter math mode using ``$``. Also, 

diff --git a/src/libkstapp/labelrenderer.cpp b/src/libkstapp/labelrenderer.cpp
@@ -27,6 +27,7 @@
 #include "applicationsettings.h"
 
 #include <QDebug>
+#include <cstdio>
 
 const double subscript_scale = 0.60;
 const double subscript_drop = 0.16;
@@ -111,13 +112,29 @@ void renderLabel(RenderContext& rc, Label::Chunk *fi, bool cache, bool draw) {
         bool ok = false;
         const QString s = fi->text.mid(1);
         const double eqResult(Equations::interpret(store, s.toLatin1(), &ok, s.length()));
-        txt = QString::number(eqResult, 'g', rc.precision);
+        if (fi->formated) {
+          const int strlen = 100;
+          char cstring[strlen];
+          QByteArray format = fi->format.toLatin1();
+          snprintf(cstring, strlen, format.data(), eqResult); // not using QString::asprintf() because it isn't in qt4.
+          txt = QString(cstring);
+        } else {
+          txt = QString::number(eqResult, 'g', rc.precision);
+        }
       } else {
         Kst::ObjectPtr op = store->retrieveObject(fi->text);
         Kst::ScalarPtr scp = Kst::kst_cast<Kst::Scalar>(op);
         if (scp) {
           KstReadLocker l(scp);
-          txt = QString::number(scp->value(), 'g', rc.precision);
+          if (fi->formated) {
+            const int strlen = 100;
+            char cstring[strlen];
+            QByteArray format = fi->format.toLatin1();
+            snprintf(cstring, strlen, format.data(), scp->value()); // not using QString::asprintf() because it isn't in qt4.
+            txt = QString(cstring);
+          } else {
+            txt = QString::number(scp->value(), 'g', rc.precision);
+          }
           if (cache) {
             rc.addObject(scp);
           }
@@ -154,7 +171,16 @@ void renderLabel(RenderContext& rc, Label::Chunk *fi, bool cache, bool draw) {
           if (ok) {
             KstReadLocker l(vp);
             const double vVal(vp->value()[int(idx)]);
-            txt = QString::number(vVal, 'g', rc.precision);
+            if (fi->formated) {
+              const int strlen = 100;
+              char cstring[strlen];
+              QByteArray format = fi->format.toLatin1();
+              snprintf(cstring, strlen, format.data(), vVal); // not using QString::asprintf() because it isn't in qt4.
+              txt = QString(cstring);
+            } else {
+              txt = QString::number(vVal, 'g', rc.precision);
+            }
+
             if (cache) {
               rc.addObject(vp);
             }

diff --git a/src/libkstmath/labelparser.cpp b/src/libkstmath/labelparser.cpp
@@ -35,7 +35,7 @@ using namespace Label;
 #endif
 
 Chunk::Chunk(Chunk *parent, VOffset dir, bool isGroup, bool inherit)
-: next(0L), prev(0L), up(0L), down(0L), group(0L), scalar(false), linebreak(false), tab(false), vector(false), vOffset(dir) {
+: next(0L), prev(0L), up(0L), down(0L), group(0L), scalar(false), linebreak(false), tab(false), vector(false), formated(false), vOffset(dir) {
   assert(parent || vOffset == None);
   if (parent) {  // attach and inherit
     switch (vOffset) {
@@ -622,6 +622,10 @@ static Chunk *parseInternal(Chunk *ctail, const QString& txt, uint& start, uint
           int vectorIndexEnd = -1;
           int bracketStack = 1;
           int pos = -1;
+          bool format = false;
+          int formatIndexStart = 0;
+          int formatIndexEnd = 0;
+
           bool equation = txt[i + 1] == '=';
           for (uint searchPt = i + 1; bracketStack != 0 && searchPt < cnt; ++searchPt) {
             if (txt[searchPt] == ']') {
@@ -644,6 +648,19 @@ static Chunk *parseInternal(Chunk *ctail, const QString& txt, uint& start, uint
             return 0L;
           }
 
+          if (pos+3 < cnt) { // ]{%f} is min size.
+            if ((txt[pos+1]=='{') && (txt[pos+2] == '%')) {
+              formatIndexStart = pos+1;
+              for (uint searchPt = pos + 2; searchPt < cnt; ++searchPt) {
+                if (txt[searchPt] == '}') {
+                  formatIndexEnd = searchPt;
+                  format = true;
+                  break;
+                }
+              }
+            }
+          }
+
           if (ctail->locked() || !ctail->text.isEmpty()) {
             if (ctail->vOffset != Chunk::None) {
               ctail = new Chunk(ctail->prev, Chunk::None, false, true);
@@ -660,7 +677,15 @@ static Chunk *parseInternal(Chunk *ctail, const QString& txt, uint& start, uint
             ctail->text = txt.mid(i + 1, pos - i - 1).trimmed();
             ctail->scalar = true;
           }
-          i = uint(pos);
+          if (format) {
+            i = uint(formatIndexEnd);
+            ctail->formated = true;
+            ctail->format = txt.mid(formatIndexStart+1, formatIndexEnd - formatIndexStart-1);
+
+            qDebug() << ctail->format;
+          } else {
+            i = uint(pos);
+          }
         }
         break;
       default:

diff --git a/src/libkstmath/labelparser.h b/src/libkstmath/labelparser.h
@@ -63,6 +63,7 @@ namespace Label {
     bool linebreak : 1;
     bool tab : 1;
     bool vector : 1;
+    bool formated : 1;
     VOffset vOffset
 #ifndef Q_OS_WIN32
     : 2
@@ -71,6 +72,7 @@ namespace Label {
     ChunkAttributes attributes;
     QString text;
     QString expression;
+    QString format;
   };
 
 

diff --git a/src/widgets/labelbuilder.cpp b/src/widgets/labelbuilder.cpp
@@ -72,6 +72,9 @@ void LabelBuilder::showHelp() {
                     "e.g. <FONT FACE=\"Courier New, monospace\">[=[GYRO1:Mean"
                     "(X4)]/[GYRO1:Sigma (X4)]]</FONT></P>"
 
+                    "<P STYLE=\"margin-bottom: 0in\"><B>Formatting:</B> Numbers can be formatted using C printf formats. e.g., "
+                    "<FONT FACE=\"Courier New, monospace\">[GYRO1:Mean (X4)]{%4.2f}</FONT>"
+
                     "<P ALIGN=LEFT STYLE=\"margin-bottom: 0in\"><FONT SIZE=4><B>Supported LaTeX Subset</B></FONT><br>"
                     "Labels in <i>kst</i> "
                     "support a derivative subset of LaTeX. For example, to display the equation for the area of a "