pyqtgraph/graphicsItems/TextItem.py

from ..Qt import QtCore, QtGui
from ..Point import Point
from .UIGraphicsItem import *
from .. import functions as fn

class TextItem(UIGraphicsItem):
    """
    GraphicsItem displaying unscaled text (the text will always appear normal even inside a scaled ViewBox). 
    """
    def __init__(self, text='', color=(200,200,200), html=None, anchor=(0,0), border=None, fill=None, angle=0):
        """
        ==============  =================================================================================
        **Arguments:**
        *text*          The text to display
        *color*         The color of the text (any format accepted by pg.mkColor)
        *html*          If specified, this overrides both *text* and *color*
        *anchor*        A QPointF or (x,y) sequence indicating what region of the text box will
                        be anchored to the item's position. A value of (0,0) sets the upper-left corner
                        of the text box to be at the position specified by setPos(), while a value of (1,1)
                        sets the lower-right corner.
        *border*        A pen to use when drawing the border
        *fill*          A brush to use when filling within the border
        ==============  =================================================================================
        """
        
        ## not working yet
        #*angle*      Angle in degrees to rotate text (note that the rotation assigned in this item's 
                     #transformation will be ignored)
                     
        self.anchor = Point(anchor)
        #self.angle = 0
        UIGraphicsItem.__init__(self)
        self.textItem = QtGui.QGraphicsTextItem()
        self.textItem.setParentItem(self)
        self.lastTransform = None
        self._bounds = QtCore.QRectF()
        if html is None:
            self.setText(text, color)
        else:
            self.setHtml(html)
        self.fill = fn.mkBrush(fill)
        self.border = fn.mkPen(border)
        self.rotate(angle)
        self.setFlag(self.ItemIgnoresTransformations)  ## This is required to keep the text unscaled inside the viewport

    def setText(self, text, color=(200,200,200)):
        color = fn.mkColor(color)
        self.textItem.setDefaultTextColor(color)
        self.textItem.setPlainText(text)
        self.updateText()
        #html = '<span style="color: #%s; text-align: center;">%s</span>' % (color, text)
        #self.setHtml(html)
        
    def updateAnchor(self):
        pass
        #self.resetTransform()
        #self.translate(0, 20)
        
    def setPlainText(self, *args):
        self.textItem.setPlainText(*args)
        self.updateText()
        
    def setHtml(self, *args):
        self.textItem.setHtml(*args)
        self.updateText()
        
    def setTextWidth(self, *args):
        self.textItem.setTextWidth(*args)
        self.updateText()
        
    def setFont(self, *args):
        self.textItem.setFont(*args)
        self.updateText()
        
    #def setAngle(self, angle):
        #self.angle = angle
        #self.updateText()
        
        
    def updateText(self):
        
        ## Needed to maintain font size when rendering to image with increased resolution
        self.textItem.resetTransform()
        #self.textItem.rotate(self.angle)
        if self._exportOpts is not False and 'resolutionScale' in self._exportOpts:
            s = self._exportOpts['resolutionScale']
            self.textItem.scale(s, s)
        
        #br = self.textItem.mapRectToParent(self.textItem.boundingRect())
        self.textItem.setPos(0,0)
        br = self.textItem.boundingRect()
        apos = self.textItem.mapToParent(Point(br.width()*self.anchor.x(), br.height()*self.anchor.y()))
        #print br, apos
        self.textItem.setPos(-apos.x(), -apos.y())
        
    #def textBoundingRect(self):
        ### return the bounds of the text box in device coordinates
        #pos = self.mapToDevice(QtCore.QPointF(0,0))
        #if pos is None:
            #return None
        #tbr = self.textItem.boundingRect()
        #return QtCore.QRectF(pos.x() - tbr.width()*self.anchor.x(), pos.y() - tbr.height()*self.anchor.y(), tbr.width(), tbr.height())


    def viewRangeChanged(self):
        self.updateText()

    def boundingRect(self):
        return self.textItem.mapToParent(self.textItem.boundingRect()).boundingRect()
        
    def paint(self, p, *args):
        tr = p.transform()
        if self.lastTransform is not None:
            if tr != self.lastTransform:
                self.viewRangeChanged()
        self.lastTransform = tr
        
        if self.border.style() != QtCore.Qt.NoPen or self.fill.style() != QtCore.Qt.NoBrush:
            p.setPen(self.border)
            p.setBrush(self.fill)
            p.setRenderHint(p.Antialiasing, True)
            p.drawPolygon(self.textItem.mapToParent(self.textItem.boundingRect()))