histogram.py

"""
@package modules.histogram

Plotting histogram based on d.histogram

Classes:
 - histogram::BufferedWindow
 - histogram::HistogramFrame
 - histogram::HistogramToolbar

(C) 2007, 2010-2011 by the GRASS Development Team

This program is free software under the GNU General Public License
(>=v2). Read the file COPYING that comes with GRASS for details.

@author Michael Barton
@author Various updates by Martin Landa <landa.martin gmail.com>
"""

import os
import sys

import wx

from core import globalvar
from core.render import Map
from gui_core.forms import GUI
from mapdisp.gprint import PrintOptions
from core.utils import GetLayerNameFromCmd
from gui_core.dialogs import GetImageHandlers, ImageSizeDialog
from gui_core.preferences import DefaultFontDialog
from core.debug import Debug
from core.gcmd import GError
from gui_core.toolbars import BaseToolbar, BaseIcons
from gui_core.wrap import PseudoDC, Menu, EmptyBitmap, NewId, BitmapFromImage


class BufferedWindow(wx.Window):
    """A Buffered window class.

    When the drawing needs to change, you app needs to call the
    UpdateHist() method. Since the drawing is stored in a bitmap, you
    can also save the drawing to file by calling the
    SaveToFile(self,file_name,file_type) method.
    """

    def __init__(self, parent, id=wx.ID_ANY,
                 style=wx.NO_FULL_REPAINT_ON_RESIZE,
                 Map=None, **kwargs):

        wx.Window.__init__(self, parent, id=id, style=style, **kwargs)

        self.parent = parent
        self.Map = Map
        self.mapname = self.parent.mapname

        #
        # Flags
        #
        self.render = True  # re-render the map from GRASS or just redraw image
        self.resize = False  # indicates whether or not a resize event has taken place
        self.dragimg = None  # initialize variable for map panning
        self.pen = None     # pen for drawing zoom boxes, etc.
        self._oldfont = self._oldencoding = None

        #
        # Event bindings
        #
        self.Bind(wx.EVT_PAINT, self.OnPaint)
        self.Bind(wx.EVT_SIZE, self.OnSize)
        self.Bind(wx.EVT_IDLE, self.OnIdle)

        #
        # Render output objects
        #
        self.mapfile = None  # image file to be rendered
        self.img = None      # wx.Image object (self.mapfile)

        self.imagedict = {}  # images and their PseudoDC ID's for painting and dragging

        self.pdc = PseudoDC()
        # will store an off screen empty bitmap for saving to file
        self._buffer = EmptyBitmap(
            max(1, self.Map.width),
            max(1, self.Map.height))

        # make sure that extents are updated at init
        self.Map.region = self.Map.GetRegion()
        self.Map.SetRegion()

        self.Bind(wx.EVT_ERASE_BACKGROUND, lambda x: None)

    def Draw(self, pdc, img=None, drawid=None,
             pdctype='image', coords=[0, 0, 0, 0]):
        """Draws histogram or clears window
        """
        if drawid is None:
            if pdctype == 'image':
                drawid = imagedict[img]
            elif pdctype == 'clear':
                drawid is None
            else:
                drawid = NewId()
        else:
            pdc.SetId(drawid)

        pdc.BeginDrawing()

        Debug.msg(
            3, "BufferedWindow.Draw(): id=%s, pdctype=%s, coord=%s" %
            (drawid, pdctype, coords))

        if pdctype == 'clear':  # erase the display
            bg = wx.WHITE_BRUSH
            pdc.SetBackground(bg)
            pdc.Clear()
            self.Refresh()
            pdc.EndDrawing()
            return

        if pdctype == 'image':
            bg = wx.TRANSPARENT_BRUSH
            pdc.SetBackground(bg)
            bitmap = BitmapFromImage(img)
            w, h = bitmap.GetSize()
            pdc.DrawBitmap(
                bitmap, coords[0],
                coords[1],
                True)  # draw the composite map
            pdc.SetIdBounds(drawid, (coords[0], coords[1], w, h))

        pdc.EndDrawing()
        self.Refresh()

    def OnPaint(self, event):
        """Draw psuedo DC to buffer
        """
        dc = wx.BufferedPaintDC(self, self._buffer)

        # use PrepareDC to set position correctly
        # probably does nothing, removed from wxPython 2.9
        # self.PrepareDC(dc)
        # we need to clear the dc BEFORE calling PrepareDC
        bg = wx.Brush(self.GetBackgroundColour())
        dc.SetBackground(bg)
        dc.Clear()
        # create a clipping rect from our position and size
        # and the Update Region
        rgn = self.GetUpdateRegion()
        r = rgn.GetBox()
        # draw to the dc using the calculated clipping rect
        self.pdc.DrawToDCClipped(dc, r)

    def OnSize(self, event):
        """Init image size to match window size
        """
        # set size of the input image
        self.Map.width, self.Map.height = self.GetClientSize()

        # Make new off screen bitmap: this bitmap will always have the
        # current drawing in it, so it can be used to save the image to
        # a file, or whatever.
        self._buffer = EmptyBitmap(self.Map.width, self.Map.height)

        # get the image to be rendered
        self.img = self.GetImage()

        # update map display
        if self.img and self.Map.width + self.Map.height > 0:  # scale image during resize
            self.img = self.img.Scale(self.Map.width, self.Map.height)
            self.render = False
            self.UpdateHist()

        # re-render image on idle
        self.resize = True

    def OnIdle(self, event):
        """Only re-render a histogram image from GRASS during idle
        time instead of multiple times during resizing.
        """
        if self.resize:
            self.render = True
            self.UpdateHist()
        event.Skip()

    def SaveToFile(self, FileName, FileType, width, height):
        """This will save the contents of the buffer to the specified
        file. See the wx.Windows docs for wx.Bitmap::SaveFile for the
        details
        """
        busy = wx.BusyInfo(_("Please wait, exporting image..."),
                           parent=self)
        wx.GetApp().Yield()

        self.Map.ChangeMapSize((width, height))
        ibuffer = EmptyBitmap(max(1, width), max(1, height))
        self.Map.Render(force=True, windres=True)
        img = self.GetImage()
        self.Draw(self.pdc, img, drawid=99)
        dc = wx.BufferedDC(None, ibuffer)
        dc.Clear()
        # probably does nothing, removed from wxPython 2.9
        # self.PrepareDC(dc)
        self.pdc.DrawToDC(dc)
        ibuffer.SaveFile(FileName, FileType)

        del busy

    def GetImage(self):
        """Converts files to wx.Image
        """
        if self.Map.mapfile and os.path.isfile(self.Map.mapfile) and \
                os.path.getsize(self.Map.mapfile):
            img = wx.Image(self.Map.mapfile, wx.BITMAP_TYPE_ANY)
        else:
            img = None

        self.imagedict[img] = 99  # set image PeudoDC ID
        return img

    def UpdateHist(self, img=None):
        """Update canvas if histogram options changes or window
        changes geometry
        """
        Debug.msg(
            2, "BufferedWindow.UpdateHist(%s): render=%s" %
            (img, self.render))
        
        if not self.render:
            return
        
        # render new map images
        # set default font and encoding environmental variables
        if "GRASS_FONT" in os.environ:
            self._oldfont = os.environ["GRASS_FONT"]
        if self.parent.font:
            os.environ["GRASS_FONT"] = self.parent.font
        if "GRASS_ENCODING" in os.environ:
            self._oldencoding = os.environ["GRASS_ENCODING"]
        if self.parent.encoding is not None and self.parent.encoding != "ISO-8859-1":
            os.environ[GRASS_ENCODING] = self.parent.encoding

        # using active comp region
        self.Map.GetRegion(update=True)

        self.Map.width, self.Map.height = self.GetClientSize()
        self.mapfile = self.Map.Render(force=self.render)
        self.Map.GetRenderMgr().renderDone.connect(self.UpdateHistDone)

    def UpdateHistDone(self):
        """Histogram image generated, finish rendering."""
        self.img = self.GetImage()
        self.resize = False

        if not self.img:
            return
        try:
            id = self.imagedict[self.img]
        except:
            return

        # paint images to PseudoDC
        self.pdc.Clear()
        self.pdc.RemoveAll()
        self.Draw(self.pdc, self.img, drawid=id)  # draw map image background

        self.resize = False

        # update statusbar
        self.Map.SetRegion()
        self.parent.statusbar.SetStatusText(
            "Image/Raster map <%s>" %
            self.parent.mapname)

        # set default font and encoding environmental variables
        if self._oldfont:
            os.environ["GRASS_FONT"] = self._oldfont
        if self._oldencoding:
            os.environ["GRASS_ENCODING"] = self._oldencoding

    def EraseMap(self):
        """Erase the map display
        """
        self.Draw(self.pdc, pdctype='clear')


class HistogramFrame(wx.Frame):
    """Main frame for hisgram display window. Uses d.histogram
    rendered onto canvas
    """

    def __init__(self, parent, giface, id=wx.ID_ANY,
                 title=_("GRASS GIS Histogramming Tool (d.histogram)"),
                 size=wx.Size(500, 350),
                 style=wx.DEFAULT_FRAME_STYLE, **kwargs):
        wx.Frame.__init__(
            self,
            parent,
            id,
            title,
            size=size,
            style=style,
            **kwargs)
        self.SetIcon(
            wx.Icon(
                os.path.join(
                    globalvar.ICONDIR,
                    'grass.ico'),
                wx.BITMAP_TYPE_ICO))

        self._giface = giface
        self.Map = Map()         # instance of render.Map to be associated with display
        self.layer = None          # reference to layer with histogram

        # Init variables
        self.params = {}  # previously set histogram parameters
        self.propwin = ''  # ID of properties dialog

        self.font = ""
        self.encoding = 'ISO-8859-1'  # default encoding for display fonts

        self.toolbar = HistogramToolbar(parent=self)
        # workaround for http://trac.wxwidgets.org/ticket/13888
        if sys.platform != 'darwin':
            self.SetToolBar(self.toolbar)

        # find selected map
        # might by moved outside this class
        # setting to None but honestly we do not handle no map case
        # TODO: when self.mapname is None content of map window is showed
        self.mapname = None
        layers = self._giface.GetLayerList().GetSelectedLayers(checkedOnly=False)
        if len(layers) > 0:
            self.mapname = layers[0].maplayer.name

        # Add statusbar
        self.statusbar = self.CreateStatusBar(number=1, style=0)
        # self.statusbar.SetStatusWidths([-2, -1])
        hist_frame_statusbar_fields = ["Histogramming %s" % self.mapname]
        for i in range(len(hist_frame_statusbar_fields)):
            self.statusbar.SetStatusText(hist_frame_statusbar_fields[i], i)

        # Init map display
        self.InitDisplay()  # initialize region values

        # initialize buffered DC
        self.HistWindow = BufferedWindow(
            self, id=wx.ID_ANY, Map=self.Map)  # initialize buffered DC

        # Bind various events
        self.Bind(wx.EVT_CLOSE, self.OnCloseWindow)

        # Init print module and classes
        self.printopt = PrintOptions(self, self.HistWindow)

        # Add layer to the map
        self.layer = self.Map.AddLayer(
            ltype="command",
            name='histogram',
            command=[
                ['d.histogram']],
            active=False,
            hidden=False,
            opacity=1,
            render=False)
        if self.mapname:
            self.SetHistLayer(self.mapname, None)
        else:
            self.OnErase(None)
            wx.CallAfter(self.OnOptions, None)

    def InitDisplay(self):
        """Initialize histogram display, set dimensions and region
        """
        self.width, self.height = self.GetClientSize()
        self.Map.geom = self.width, self.height

    def OnOptions(self, event):
        """Change histogram settings"""
        cmd = ['d.histogram']
        if self.mapname != '':
            cmd.append('map=%s' % self.mapname)
        module = GUI(parent=self)
        module.ParseCommand(
            cmd,
            completed=(
                self.GetOptData,
                None,
                self.params))

    def GetOptData(self, dcmd, layer, params, propwin):
        """Callback method for histogram command generated by dialog
        created in menuform.py
        """
        if dcmd:
            name, found = GetLayerNameFromCmd(dcmd, fullyQualified=True,
                                              layerType='raster')
            if not found:
                GError(parent=propwin,
                       message=_("Raster map <%s> not found") % name)
                return

            self.SetHistLayer(name, dcmd)
        self.params = params
        self.propwin = propwin
        self.HistWindow.UpdateHist()

    def SetHistLayer(self, name, cmd=None):
        """Set histogram layer
        """
        self.mapname = name
        if not cmd:
            cmd = ['d.histogram', ('map=%s' % self.mapname)]
        self.layer = self.Map.ChangeLayer(layer=self.layer,
                                          command=[cmd],
                                          active=True)

        return self.layer

    def SetHistFont(self, event):
        """Set font for histogram. If not set, font will be default
        display font.
        """
        dlg = DefaultFontDialog(parent=self, id=wx.ID_ANY,
                                title=_('Select font for histogram text'))
        dlg.fontlb.SetStringSelection(self.font, True)

        if dlg.ShowModal() == wx.ID_CANCEL:
            dlg.Destroy()
            return

        # set default font type, font, and encoding to whatever selected in
        # dialog
        if dlg.font is not None:
            self.font = dlg.font
        if dlg.encoding is not None:
            self.encoding = dlg.encoding

        dlg.Destroy()
        self.HistWindow.UpdateHist()

    def OnErase(self, event):
        """Erase the histogram display
        """
        self.HistWindow.Draw(self.HistWindow.pdc, pdctype='clear')

    def OnRender(self, event):
        """Re-render histogram
        """
        self.HistWindow.UpdateHist()

    def GetWindow(self):
        """Get buffered window"""
        return self.HistWindow

    def SaveToFile(self, event):
        """Save to file
        """
        filetype, ltype = GetImageHandlers(self.HistWindow.img)

        # get size
        dlg = ImageSizeDialog(self)
        dlg.CentreOnParent()
        if dlg.ShowModal() != wx.ID_OK:
            dlg.Destroy()
            return
        width, height = dlg.GetValues()
        dlg.Destroy()

        # get filename
        dlg = wx.FileDialog(parent=self,
                            message=_("Choose a file name to save the image "
                                      "(no need to add extension)"),
                            wildcard=filetype,
                            style=wx.FD_SAVE | wx.FD_OVERWRITE_PROMPT)

        if dlg.ShowModal() == wx.ID_OK:
            path = dlg.GetPath()
            if not path:
                dlg.Destroy()
                return

            base, ext = os.path.splitext(path)
            fileType = ltype[dlg.GetFilterIndex()]['type']
            extType = ltype[dlg.GetFilterIndex()]['ext']
            if ext != extType:
                path = base + '.' + extType

            self.HistWindow.SaveToFile(path, fileType,
                                       width, height)

        self.HistWindow.UpdateHist()
        dlg.Destroy()

    def PrintMenu(self, event):
        """Print options and output menu
        """
        point = wx.GetMousePosition()
        printmenu = Menu()
        # Add items to the menu
        setup = wx.MenuItem(printmenu, id=wx.ID_ANY, text=_('Page setup'))
        printmenu.AppendItem(setup)
        self.Bind(wx.EVT_MENU, self.printopt.OnPageSetup, setup)

        preview = wx.MenuItem(printmenu, id=wx.ID_ANY, text=_('Print preview'))
        printmenu.AppendItem(preview)
        self.Bind(wx.EVT_MENU, self.printopt.OnPrintPreview, preview)

        doprint = wx.MenuItem(printmenu, id=wx.ID_ANY, text=_('Print display'))
        printmenu.AppendItem(doprint)
        self.Bind(wx.EVT_MENU, self.printopt.OnDoPrint, doprint)

        # Popup the menu.  If an item is selected then its handler
        # will be called before PopupMenu returns.
        self.PopupMenu(printmenu)
        printmenu.Destroy()

    def OnQuit(self, event):
        self.Close(True)

    def OnCloseWindow(self, event):
        """Window closed
        Also remove associated rendered images
        """
        try:
            self.propwin.Close(True)
        except:
            pass
        self.Map.Clean()
        self.Destroy()


class HistogramToolbar(BaseToolbar):
    """Histogram toolbar (see histogram.py)
    """

    def __init__(self, parent):
        BaseToolbar.__init__(self, parent)

        # workaround for http://trac.wxwidgets.org/ticket/13888
        if sys.platform == 'darwin':
            parent.SetToolBar(self)

        self.InitToolbar(self._toolbarData())

        # realize the toolbar
        self.Realize()

    def _toolbarData(self):
        """Toolbar data"""
        return self._getToolbarData((('histogram', BaseIcons["histogramD"],
                                      self.parent.OnOptions),
                                     ('render', BaseIcons["display"],
                                      self.parent.OnRender),
                                     ('erase', BaseIcons["erase"],
                                      self.parent.OnErase),
                                     ('font', BaseIcons["font"],
                                      self.parent.SetHistFont),
                                     (None, ),
                                     ('save', BaseIcons["saveFile"],
                                      self.parent.SaveToFile),
                                     ('hprint', BaseIcons["print"],
                                      self.parent.PrintMenu),
                                     (None, ),
                                     ('quit', BaseIcons["quit"],
                                      self.parent.OnQuit))
                                    )