Add a tentative sleep prevention for linux.

I wasn't able to test this, but at least it won't hurt and it's better
than nothing.
I tested the command execution and it doesn't give an error or anything
but I'm unable to get my setup to suspend so I can't test the prevention
of suspend.
This is for Linux support on issue #46

diff --git a/Cura/gui/printWindow.py b/Cura/gui/printWindow.py
index 35be4a8385f1be33c478b6cce3361ecf760f86e3..74be922d84fd95339f53b0c981b25e705109bb49 100644 (file)
--- a/Cura/gui/printWindow.py
+++ b/Cura/gui/printWindow.py
@@ -6,10 +6,11 @@ import time
 import sys
 import os
 import ctypes
+import subprocess
 
 #TODO: This does not belong here!
 if sys.platform.startswith('win'):
-       def preventComputerFromSleeping(prevent):
+       def preventComputerFromSleeping(frame, prevent):
                """
                Function used to prevent the computer from going into sleep mode.
                :param prevent: True = Prevent the system from going to sleep from this point on.
@@ -34,7 +35,7 @@ elif sys.platform.startswith('darwin'):
        frameworkPath=objc.pathForFramework("/System/Library/Frameworks/IOKit.framework"),
        globals=globals())
        objc.loadBundleFunctions(bundle, globals(), [("IOPMAssertionCreateWithName", b"i@I@o^I")])
-       def preventComputerFromSleeping(prevent):
+       def preventComputerFromSleeping(frame, prevent):
                if prevent:
                        success, preventComputerFromSleeping.assertionID = IOPMAssertionCreateWithName(kIOPMAssertionTypeNoDisplaySleep, kIOPMAssertionLevelOn, "Cura is printing", None)
                        if success != kIOReturnSuccess:
@@ -44,8 +45,13 @@ elif sys.platform.startswith('darwin'):
                                IOPMAssertionRelease(preventComputerFromSleeping.assertionID)
                                preventComputerFromSleeping.assertionID = None
 else:
-       def preventComputerFromSleeping(prevent):
-               pass
+       def preventComputerFromSleeping(frame, prevent):
+                if os.path.isfile("/usr/bin/xdg-screensaver"):
+                        try:
+                                cmd = ['xdg-screensaver', 'suspend' if prevent else 'resume', str(frame.GetHandle())]
+                                subprocess.call(cmd)
+                        except:
+                                pass
 
 class printWindowPlugin(wx.Frame):
        def __init__(self, parent, printerConnection, filename):
@@ -252,7 +258,7 @@ class printWindowPlugin(wx.Frame):
                        self._printerConnection.closeActiveConnection()
                self._printerConnection.removeCallback(self._doPrinterConnectionUpdate)
                #TODO: When multiple printer windows are open, closing one will enable sleeping again.
-               preventComputerFromSleeping(False)
+               preventComputerFromSleeping(self, False)
                self.Destroy()
 
        def OnTermEnterLine(self, e):
@@ -355,7 +361,7 @@ class printWindowPlugin(wx.Frame):
                        self.SetTitle(info.replace('\n', ', '))
                if connection.isPrinting() != self._isPrinting:
                        self._isPrinting = connection.isPrinting()
-                       preventComputerFromSleeping(self._isPrinting)
+                       preventComputerFromSleeping(self, self._isPrinting)
 
 class printWindowBasic(wx.Frame):
        """
@@ -449,7 +455,7 @@ class printWindowBasic(wx.Frame):
                        self._printerConnection.closeActiveConnection()
                self._printerConnection.removeCallback(self._doPrinterConnectionUpdate)
                #TODO: When multiple printer windows are open, closing one will enable sleeping again.
-               preventComputerFromSleeping(False)
+               preventComputerFromSleeping(self, False)
                self.Destroy()
 
        def OnConnect(self, e):
@@ -499,7 +505,7 @@ class printWindowBasic(wx.Frame):
                self.statsText.SetLabel(info)
                if connection.isPrinting() != self._isPrinting:
                        self._isPrinting = connection.isPrinting()
-                       preventComputerFromSleeping(self._isPrinting)
+                       preventComputerFromSleeping(self, self._isPrinting)
 
 
        def _updateButtonStates(self):