Configurable GridItem tick spacing and pen color (#101)

pyqtgraph/graphicsItems/GridItem.py

@@ -3,6 +3,7 @@ from .UIGraphicsItem import *
 import numpy as np
 from ..Point import Point
 from .. import functions as fn
+from .. import getConfigOption
 
 __all__ = ['GridItem']
 class GridItem(UIGraphicsItem):
@@ -13,13 +14,72 @@ class GridItem(UIGraphicsItem):
     Automatically determines what divisions to use.
     """
 
-    def __init__(self):
+    def __init__(self, pen='default', textPen='default'):
         UIGraphicsItem.__init__(self)
         #QtGui.QGraphicsItem.__init__(self, *args)
         #self.setFlag(QtGui.QGraphicsItem.ItemClipsToShape)
         #self.setCacheMode(QtGui.QGraphicsItem.DeviceCoordinateCache)
 
+        self.opts = {}
+
+        self.setPen(pen)
+        self.setTextPen(textPen)
+        self.setTickSpacing(x=[None, None, None], y=[None, None, None])
+
+
+    def setPen(self, *args, **kwargs):
+        """Set the pen used to draw the grid."""
+        if kwargs == {} and (args == () or args == ('default',)):
+            self.opts['pen'] = fn.mkPen(getConfigOption('foreground'))
+        else:
+            self.opts['pen'] = fn.mkPen(*args, **kwargs)
+
         self.picture = None
+        self.update()
+
+
+    def setTextPen(self, *args, **kwargs):
+        """Set the pen used to draw the texts."""
+        if kwargs == {} and (args == () or args == ('default',)):
+            self.opts['textPen'] = fn.mkPen(getConfigOption('foreground'))
+        else:
+            if args == (None,):
+                self.opts['textPen'] = None
+            else:
+                self.opts['textPen'] = fn.mkPen(*args, **kargs)
+
+        self.picture = None
+        self.update()
+
+
+    def setTickSpacing(self, x=None, y=None):
+        """
+        Set the grid tick spacing to use.
+
+        Tick spacing for each axis shall be specified as an array of
+        descending values, one for each tick scale. When the value
+        is set to None, grid line distance is chosen automatically
+        for this particular level.
+
+        Example:
+            Default setting of 3 scales for each axis:
+            setTickSpacing(x=[None, None, None], y=[None, None, None])
+
+            Single scale with distance of 1.0 for X axis, Two automatic
+            scales for Y axis:
+            setTickSpacing(x=[1.0], y=[None, None])
+
+            Single scale with distance of 1.0 for X axis, Two scales
+            for Y axis, one with spacing of 1.0, other one automatic:
+            setTickSpacing(x=[1.0], y=[1.0, None])
+        """
+        self.opts['tickSpacing'] = (x or self.opts['tickSpacing'][0],
+                                    y or self.opts['tickSpacing'][1])
+
+        self.grid_depth = max([len(s) for s in self.opts['tickSpacing']])
+
+        self.picture = None
+        self.update()
 
 
     def viewRangeChanged(self):
@@ -48,7 +108,6 @@ class GridItem(UIGraphicsItem):
         p = QtGui.QPainter()
         p.begin(self.picture)
         
-        dt = fn.invertQTransform(self.viewTransform())
         vr = self.getViewWidget().rect()
         unit = self.pixelWidth(), self.pixelHeight()
         dim = [vr.width(), vr.height()]
@@ -62,10 +121,22 @@ class GridItem(UIGraphicsItem):
             x = ul[1]
             ul[1] = br[1]
             br[1] = x
-        for i in [2,1,0]:   ## Draw three different scales of grid
+
+        lastd = [None, None]
+        for i in range(self.grid_depth - 1, -1, -1):
             dist = br-ul
             nlTarget = 10.**i
+
             d = 10. ** np.floor(np.log10(abs(dist/nlTarget))+0.5)
+            for ax in range(0,2):
+                ts = self.opts['tickSpacing'][ax]
+                try:
+                    if ts[i] is not None:
+                        d[ax] = ts[i]
+                except IndexError:
+                    pass
+                lastd[ax] = d[ax]
+
             ul1 = np.floor(ul / d) * d
             br1 = np.ceil(br / d) * d
             dist = br1-ul1
@@ -76,12 +147,25 @@ class GridItem(UIGraphicsItem):
             #print "  d", d
             #print "  nl", nl
             for ax in range(0,2):  ## Draw grid for both axes
+                if i >= len(self.opts['tickSpacing'][ax]):
+                    continue
+                if d[ax] < lastd[ax]:
+                    continue
+
                 ppl = dim[ax] / nl[ax]
-                c = np.clip(3.*(ppl-3), 0., 30.)
+                c = np.clip(5.*(ppl-3), 0., 50.)
-                linePen = QtGui.QPen(QtGui.QColor(255, 255, 255, c)) 
+
-                textPen = QtGui.QPen(QtGui.QColor(255, 255, 255, c*2)) 
+                linePen = self.opts['pen']
-                #linePen.setCosmetic(True)
+                lineColor = self.opts['pen'].color()
-                #linePen.setWidth(1)
+                lineColor.setAlpha(c)
+                linePen.setColor(lineColor)
+
+                textPen = self.opts['textPen']
+                if textPen is not None:
+                    textColor = self.opts['textPen'].color()
+                    textColor.setAlpha(c * 2)
+                    textPen.setColor(textColor)
+
                 bx = (ax+1) % 2
                 for x in range(0, int(nl[ax])):
                     linePen.setCosmetic(False)
@@ -102,8 +186,7 @@ class GridItem(UIGraphicsItem):
                     if p1[ax] < min(ul[ax], br[ax]) or p1[ax] > max(ul[ax], br[ax]):
                         continue
                     p.drawLine(QtCore.QPointF(p1[0], p1[1]), QtCore.QPointF(p2[0], p2[1]))
-                    if i < 2:
+                    if i < 2 and textPen is not None:
-                        p.setPen(textPen)
                         if ax == 0:
                             x = p1[0] + unit[0]
                             y = ul[1] + unit[1] * 8.
@@ -114,7 +197,13 @@ class GridItem(UIGraphicsItem):
         tr = self.deviceTransform()
         #tr.scale(1.5, 1.5)
         p.setWorldTransform(fn.invertQTransform(tr))
-        for t in texts:
+
-            x = tr.map(t[0]) + Point(0.5, 0.5)
+        if textPen is not None and len(texts) > 0:
-            p.drawText(x, t[1])
+            # if there is at least one text, then c is set
+            textColor.setAlpha(c * 2)
+            p.setPen(QtGui.QPen(textColor))
+            for t in texts:
+                x = tr.map(t[0]) + Point(0.5, 0.5)
+                p.drawText(x, t[1])
+
         p.end()