Mouse scroll wheel! New PDF viewer demo

Demo_PDF_Viewer.py

@@ -1,79 +1,183 @@
+"""
+@created: 2018-08-19 18:00:00
+
+@author: (c) 2018 Jorj X. McKie
+
+Display a PyMuPDF Document using Tkinter
+-------------------------------------------------------------------------------
+
+Dependencies:
+-------------
+PyMuPDF, PySimpleGUI > v2.9.0, Tkinter with Tk v8.6+, Python 3
+
+
+License:
+--------
+GNU GPL V3+
+
+Description
+------------
+Read filename from command line and start display with page 1.
+Pages can be directly jumped to, or buttons for paging can be used.
+For experimental / demonstration purposes, we have included options to zoom
+into the four page quadrants (top-left, bottom-right, etc.).
+
+We also interpret keyboard events to support paging by PageDown / PageUp
+keys as if the resp. buttons were clicked. Similarly, we do not include
+a 'Quit' button. Instead, the ESCAPE key can be used, or cancelling the form.
+
+To improve paging performance, we are not directly creating pixmaps from
+pages, but instead from the fitz.DisplayList of the page. A display list
+will be stored in a list and looked up by page number. This way, zooming
+pixmaps and page re-visits will re-use a once-created display list.
+
+"""
 import sys
 import fitz
 import PySimpleGUI as sg
+from binascii import hexlify
 
-try:
+if len(sys.argv) == 1:
+    rc, fname = sg.GetFileBox('PDF Browser', 'PDF file to open', file_types=(("PDF Files", "*.pdf"),))
+    if rc is False:
+        sg.MsgBoxCancel('Cancelling')
+        exit(0)
+else:
     fname = sys.argv[1]
-except:
+
-    fname = 'C:/Python/PycharmProjects/GooeyGUI/test.pdf'
 doc = fitz.open(fname)
-title = "PyMuPDF display of '%s' (%i pages)" % (fname, len(doc))
+page_count = len(doc)
 
-def get_page(pno, zoom = 0):
+# storage for page display lists
-    page = doc[pno]
+dlist_tab = [None] * page_count
-    r = page.rect
+
-    mp = r.tl + (r.br - r.tl) * 0.5
+title = "PyMuPDF display of '%s', pages: %i" % (fname, page_count)
-    mt = r.tl + (r.tr - r.tl) * 0.5
+
-    ml = r.tl + (r.bl - r.tl) * 0.5
+
-    mr = r.tr + (r.br - r.tr) * 0.5
+def get_page(pno, zoom=0):
-    mb = r.bl + (r.br - r.bl) * 0.5
+    """Return a PNG image for a document page number. If zoom is other than 0, one of the 4 page quadrants are zoomed-in instead and the corresponding clip returned.
-    mat = fitz.Matrix(2, 2)
+
-    if zoom == 1:
+    """
+    dlist = dlist_tab[pno]  # get display list
+    if not dlist:  # create if not yet there
+        dlist_tab[pno] = doc[pno].getDisplayList()
+        dlist = dlist_tab[pno]
+    r = dlist.rect  # page rectangle
+    mp = r.tl + (r.br - r.tl) * 0.5  # rect middle point
+    mt = r.tl + (r.tr - r.tl) * 0.5  # middle of top edge
+    ml = r.tl + (r.bl - r.tl) * 0.5  # middle of left edge
+    mr = r.tr + (r.br - r.tr) * 0.5  # middle of right egde
+    mb = r.bl + (r.br - r.bl) * 0.5  # middle of bottom edge
+    mat = fitz.Matrix(2, 2)  # zoom matrix
+    if zoom == 1:  # top-left quadrant
         clip = fitz.Rect(r.tl, mp)
-    elif zoom == 4:
+    elif zoom == 4:  # bot-right quadrant
         clip = fitz.Rect(mp, r.br)
-    elif zoom == 2:
+    elif zoom == 2:  # top-right
         clip = fitz.Rect(mt, mr)
-    elif zoom == 3:
+    elif zoom == 3:  # bot-left
         clip = fitz.Rect(ml, mb)
-    if zoom == 0:
+    if zoom == 0:  # total page
-        pix = page.getPixmap(alpha = False)
+        pix = dlist.getPixmap(alpha=False)
     else:
-        pix = page.getPixmap(alpha = False, matrix = mat, clip = clip)
+        pix = dlist.getPixmap(alpha=False, matrix=mat, clip=clip)
-    return pix.getPNGData()
+    return pix.getPNGData()  # return the PNG image
 
-form = sg.FlexForm(title, return_keyboard_events=True)
 
-data = get_page(0)
+form = sg.FlexForm(title, return_keyboard_events=True, use_default_focus=False)
+
+cur_page = 0
+data = get_page(cur_page)  # show page 1 for start
 image_elem = sg.Image(data=data)
-layout = [  [image_elem],
+goto = sg.InputText(str(cur_page + 1), size=(5, 1), do_not_clear=True)
-            [sg.ReadFormButton('Next'),
+
-             sg.ReadFormButton('Prev'),
+layout = [
-             sg.ReadFormButton('First'),
+    [
-             sg.ReadFormButton('Last'),
+        sg.ReadFormButton('Next'),
-             sg.ReadFormButton('Zoom-1'),
+        sg.ReadFormButton('Prev'),
-             sg.ReadFormButton('Zoom-2'),
+        sg.Text('Page:'),
-             sg.ReadFormButton('Zoom-3'),
+        goto,
-             sg.ReadFormButton('Zoom-4'),
+    ],
-             sg.Quit()]  ]
+    [
+        sg.Text("Zoom:"),
+        sg.ReadFormButton('Top-L'),
+        sg.ReadFormButton('Top-R'),
+        sg.ReadFormButton('Bot-L'),
+        sg.ReadFormButton('Bot-R'),
+    ],
+    [image_elem],
+]
 
 form.Layout(layout)
+my_keys = ("Next", "Next:34", "Prev", "Prior:33", "Top-L", "Top-R",
+           "Bot-L", "Bot-R", "MouseWheel:Down", "MouseWheel:Up")
+zoom_buttons = ("Top-L", "Top-R", "Bot-L", "Bot-R")
+
+old_page = 0
+old_zoom = 0  # used for zoom on/off
+# the zoom buttons work in on/off mode.
 
-i = oldzoom = 0
 while True:
-    button,value = form.Read()
+    button, value = form.ReadNonBlocking()
     zoom = 0
-    if button in (None, 'Quit'):
+    force_page = False
+    if button is None and value is None:
         break
-    if button in ("Next", 'Next:34'):
+    if button is None:
-        i += 1
+        continue
-    elif button in ("Prev", "Prior:33"):
+
-        i -= 1
+    if button in ("Escape:27"):  # this spares me a 'Quit' button!
-    elif button == "First":
+        break
-        i = 0
+    # print("hex(button)", hexlify(button.encode()))
-    elif button == "Last":
+    if button[0] == chr(13):  # surprise: this is 'Enter'!
-        i = -1
+        try:
-    elif button == "Zoom-1":
+            cur_page = int(value[0]) - 1  # check if valid
-        zoom = oldzoom = 0 if oldzoom == 1 else 1
+            while cur_page < 0:
-    elif button == "Zoom-2":
+                cur_page += page_count
-        zoom = oldzoom = 0 if oldzoom == 2 else 2
+        except:
-    elif button == "Zoom-3":
+            cur_page = 0  # this guy's trying to fool me
-        zoom = oldzoom = 0 if oldzoom == 3 else 3
+        goto.Update(str(cur_page + 1))
-    elif button == "Zoom-4":
+        # goto.TKStringVar.set(str(cur_page + 1))
-        zoom = oldzoom = 0 if oldzoom == 4 else 4
+
-    try:
+    elif button in ("Next", "Next:34", "MouseWheel:Down"):
-        data = get_page(i, zoom)
+        cur_page += 1
-    except:
+    elif button in ("Prev", "Prior:33", "MouseWheel:Up"):
-        i = 0
+        cur_page -= 1
-        data = get_page(i, zoom)
+    elif button == "Top-L":
-    image_elem.Update(data=data)
+        zoom = 1
+    elif button == "Top-R":
+        zoom = 2
+    elif button == "Bot-L":
+        zoom = 3
+    elif button == "Bot-R":
+        zoom = 4
+
+    # sanitize page number
+    if cur_page >= page_count:  # wrap around
+        cur_page = 0
+    while cur_page < 0:  # we show conventional page numbers
+        cur_page += page_count
+
+    # prevent creating same data again
+    if cur_page != old_page:
+        zoom = old_zoom = 0
+        force_page = True
+
+    if button in zoom_buttons:
+        if 0 < zoom == old_zoom:
+            zoom = 0
+            force_page = True
+
+        if zoom != old_zoom:
+            force_page = True
+
+    if force_page:
+        data = get_page(cur_page, zoom)
+        image_elem.Update(data=data)
+        old_page = cur_page
+    old_zoom = zoom
+
+    # update page number field
+    if button in my_keys or not value[0]:
+        goto.Update(str(cur_page + 1))
+        # goto.TKStringVar.set(str(cur_page + 1))

PySimpleGUI.py

@@ -1027,7 +1027,6 @@ class FlexForm:
         return BuildResults(self, False, self)
 
     def KeyboardCallback(self, event ):
-        # print(".",)
         self.LastButtonClicked = None
         self.FormRemainedOpen = True
         if event.char != '':
@@ -1038,6 +1037,16 @@ class FlexForm:
             results = BuildResults(self, False, self)
         self.TKroot.quit()
 
+    def MouseWheelCallback(self, event ):
+        self.LastButtonClicked = None
+        self.FormRemainedOpen = True
+        # print(ObjToStringSingleObj(event))
+        direction = 'Down' if event.delta < 0 else 'Up'
+        self.LastKeyboardEvent = 'MouseWheel:' + direction
+        if not self.NonBlocking:
+            results = BuildResults(self, False, self)
+        self.TKroot.quit()
+
 
     def _Close(self):
         try:
@@ -1796,8 +1805,10 @@ def StartupTK(my_flex_form):
     my_flex_form.SetIcon(my_flex_form.WindowIcon)
     if my_flex_form.ReturnKeyboardEvents and not my_flex_form.NonBlocking:
         root.bind("<KeyRelease>", my_flex_form.KeyboardCallback)
+        root.bind("<MouseWheel>", my_flex_form.MouseWheelCallback)
     elif my_flex_form.ReturnKeyboardEvents:
         root.bind("<Key>", my_flex_form.KeyboardCallback)
+        root.bind("<MouseWheel>", my_flex_form.MouseWheelCallback)
 
     if my_flex_form.AutoClose:
         duration = DEFAULT_AUTOCLOSE_TIME if my_flex_form.AutoCloseDuration is None else my_flex_form.AutoCloseDuration