New "projectpath" attribute on "Project" element in the project file used to inform the root path of the project.

eric5.PROJECTPATH.patch

# HG changeset patch
# Parent e18f96b1714b2353c7988d7b274925fa12bb0343
Addition of "projectpath" attribute.

New "projectpath" attribute on "Project" element in the project file used to
inform the root path of the project. Eric5 expects project file to be saved at
the root; this hack enables the project files to be saved anywhere inside the
project directory and yet retaining the project root path for the IDE.

diff --git a/E5XML/ProjectReader.py b/E5XML/ProjectReader.py
--- a/E5XML/ProjectReader.py
+++ b/E5XML/ProjectReader.py
@@ -45,6 +45,19 @@
                         self.attribute("version", projectFileFormatVersion)
                     if self.version not in self.supportedVersions:
                         self.raiseUnsupportedFormatVersion(self.version)
+
+                    # Accept a new attribute called "projectpath" which could
+                    # tell us the actual project path *RELATIVE* to this project
+                    # file location.
+                    ppath = self.attribute("projectpath", None)
+                    if ppath is not None:
+                        # I hope I'm not polluting :p
+                        self.project.pdata["^^PROJECTPATH"] = ppath
+                        # Now because the key "^^PROJECTPATH" will only exists
+                        # if the "projectpath" attribute exists when reading the
+                        # project, this means for now, to use this feature I
+                        # have to manually add the "projectpath" attribute to
+                        # the "Project" element in the xml file.
                 elif self.name() == "Language":
                     self.project.pdata["SPELLLANGUAGE"] = [self.readElementText()]
                 elif self.name() == "ProjectWordList":
diff --git a/E5XML/ProjectWriter.py b/E5XML/ProjectWriter.py
--- a/E5XML/ProjectWriter.py
+++ b/E5XML/ProjectWriter.py
@@ -7,8 +7,11 @@
 Module implementing the writer class for writing an XML project file.
 """
 
+import os
 import time
 
+from PyQt4.QtCore import QFile
+
 from E5Gui.E5Application import e5App
 
 from .XMLStreamWriterBase import XMLStreamWriterBase
@@ -32,6 +35,7 @@
         XMLStreamWriterBase.__init__(self, device)
         
         self.pdata = e5App().getObject("Project").pdata
+        self.ppath = e5App().getObject("Project").ppath
         self.name = projectName
         
     def writeXML(self):
@@ -55,6 +59,22 @@
         # add the main tag
         self.writeStartElement("Project")
         self.writeAttribute("version", projectFileFormatVersion)
+
+        # write "projectpath" attribute, only if we have to write it
+        if ("^^PROJECTPATH" in self.pdata) and os.path.isdir(self.ppath):
+            # Someday, the "^^PROJECTPATH" testing can be removed if my hack got
+            # accepted; as without its existence in pdata the "projectpath"
+            # should never be written.
+            devc = self.device()
+            if isinstance(devc, QFile):
+                ppath = os.path.relpath(self.ppath,
+                                        os.path.dirname(devc.fileName()))
+                if ppath != '.':
+                    self.writeAttribute("projectpath", ppath)
+                    # update the project data
+                    self.pdata["^^PROJECTPATH"] = ppath
+                else:
+                    del self.pdata["^^PROJECTPATH"]
         
         # do the language (used for spell checking)
         self.writeTextElement("Language", self.pdata["SPELLLANGUAGE"][0])
diff --git a/Project/Project.py b/Project/Project.py
--- a/Project/Project.py
+++ b/Project/Project.py
@@ -613,6 +613,9 @@
         
         self.pfile = os.path.abspath(fn)
         self.ppath = os.path.abspath(os.path.dirname(fn))
+        if res:
+            self.__updateppath()
+
         self.__makePpathRe()
         
         # insert filename into list of recently opened projects
@@ -700,6 +703,8 @@
         if res:
             self.pfile = os.path.abspath(fn)
             self.ppath = os.path.abspath(os.path.dirname(fn))
+            self.__updateppath()
+
             self.__makePpathRe()
             self.name = os.path.splitext(os.path.basename(fn))[0]
             self.setDirty(False)
@@ -708,6 +713,22 @@
             self.__syncRecent()
         
         return res
+
+    def __updateppath(self):
+        """
+        Private method to update ppath relative to project file location.
+        """
+
+        # This is to set project path to a certain location relative to the
+        # project file location. We got this from "^^PROJECTPATH" value
+        # from reading the project file.
+        if "^^PROJECTPATH" not in self.pdata:
+            return
+
+        ppath = os.path.normpath(os.path.join(self.ppath,
+                                 self.pdata["^^PROJECTPATH"]))
+        if os.path.isdir(ppath):
+            self.ppath = os.path.abspath(ppath)
         
     def __readUserProperties(self):
         """