Browser viewer: Allow long tapping a word to look it up in a dictionary or search the internet for it. Fixes #1738995 [[Browser Viewer] not possible to select text on Android](https://bugs.launchpad.net/calibre/+bug/1738995)

src/pyj/read_book/flow_mode.pyj

@@ -2,6 +2,8 @@
 # License: GPL v3 Copyright: 2016, Kovid Goyal <kovid at kovidgoyal.net>
 from __python__ import bound_methods, hash_literals
 
+from select import word_at_point
+
 from dom import set_css
 from keycodes import get_key
 from read_book.globals import get_boss
@@ -164,6 +166,14 @@ def handle_gesture(gesture):
         scroll_by_page(True)
     elif gesture.type is 'next-page':
         scroll_by_page(False)
+    elif gesture.type is 'long-tap':
+        r = word_at_point(gesture.viewport_x, gesture.viewport_y)
+        if r:
+            s = document.getSelection()
+            s.removeAllRanges()
+            s.addRange(r)
+            get_boss().send_message('lookup_word', word=str(r))
+
 
 anchor_funcs = {
     'pos_for_elem': def pos_for_elem(elem):

src/pyj/read_book/overlay.pyj

@@ -16,6 +16,7 @@ from read_book.goto import create_goto_panel
 from read_book.prefs.font_size import create_font_size_panel
 from read_book.prefs.main import create_prefs_panel
 from read_book.toc import create_toc_panel
+from read_book.word_actions import create_word_actions_panel
 from session import get_device_uuid
 from widgets import create_button, create_spinner
 
@@ -309,6 +310,26 @@ class TOCOverlay: # {{{
             self.overlay.view.goto_named_destination(dest, frag)
 # }}}
 
+class WordActionsOverlay:  # {{{
+
+    def __init__(self, word, overlay):
+        self.word = word
+        self.overlay = overlay
+
+    def on_container_click(self, evt):
+        pass  # Dont allow panel to be closed by a click
+
+    def show(self, container):
+        container.style.backgroundColor = get_color('window-background')
+        container.appendChild(E.div(
+            style='padding: 1ex 1em; border-bottom: solid 1px currentColor; display:flex; justify-content: space-between',
+            E.h2(_('Lookup: {}').format(self.word)),
+                E.div(svgicon('close'), style='cursor:pointer', onclick=def(event):event.preventDefault(), event.stopPropagation(), self.overlay.hide_current_panel(event);, class_='simple-link'),
+            ))
+        container.appendChild(E.div())
+        create_word_actions_panel(container, self.word, self.overlay.hide)
+# }}}
+
 class PrefsOverlay: # {{{
 
     def __init__(self, overlay):
@@ -330,13 +351,15 @@ class PrefsOverlay: # {{{
 
 # }}}
 
-class FontSizeOverlay:
+class FontSizeOverlay:  # {{{
 
     def __init__(self, overlay):
         self.overlay = overlay
 
     def show(self, container):
         create_font_size_panel(container, self.overlay.hide_current_panel)
+# }}}
+
 
 class Overlay:
 
@@ -439,3 +462,8 @@ class Overlay:
         self.hide_current_panel()
         self.panels.push(FontSizeOverlay(self))
         self.show_current_panel()
+
+    def show_word_actions(self, word):
+        self.hide_current_panel()
+        self.panels.push(WordActionsOverlay(word, self))
+        self.show_current_panel()

src/pyj/read_book/paged_mode.pyj

@@ -4,6 +4,7 @@ from __python__ import hash_literals
 
 import traceback
 from elementmaker import E
+from select import word_at_point
 
 from dom import set_css
 from keycodes import get_key
@@ -507,6 +508,13 @@ def handle_gesture(gesture):
         scroll_by_page(True, False)
     elif gesture.type is 'next-page':
         scroll_by_page(False, False)
+    elif gesture.type is 'long-tap':
+        r = word_at_point(gesture.viewport_x, gesture.viewport_y)
+        if r:
+            s = document.getSelection()
+            s.removeAllRanges()
+            s.addRange(r)
+            get_boss().send_message('lookup_word', word=str(r))
 
 
 anchor_funcs = {

src/pyj/read_book/touch.pyj

@@ -10,6 +10,7 @@ HOLD_THRESHOLD = 750  # milliseconds
 TAP_THRESHOLD = 7  # pixels
 TAP_LINK_THRESHOLD = 5  # pixels
 PINCH_THRESHOLD = 10  # pixels
+LONG_TAP_THRESHOLD = 500  # milliseconds
 
 gesture_id = 0
 
@@ -39,7 +40,7 @@ def max_displacement(points):
 def interpret_single_gesture(touch, gesture_id):
     max_x_displacement = max_displacement(touch.viewport_x)
     max_y_displacement = max_displacement(touch.viewport_y)
-    ans = {'active':touch.active, 'is_held':touch.is_held, 'id':gesture_id}
+    ans = {'active':touch.active, 'is_held':touch.is_held, 'id':gesture_id, 'start_time': touch.ctime}
     if max(max_x_displacement, max_y_displacement) < TAP_THRESHOLD:
         ans.type = 'tap'
         ans.viewport_x = touch.viewport_x[0]
@@ -234,15 +235,10 @@ class BookTouchHandler(TouchHandler):
         gesture.from_side_margin = self.for_side_margin
         if gesture.type is 'tap':
             if gesture.is_held:
-                if not self.for_side_margin and not self.handled_tap_hold:
+                if not self.for_side_margin and not self.handled_tap_hold and window.performance.now() - gesture.start_time >= LONG_TAP_THRESHOLD:
                     self.handled_tap_hold = True
-                    fake_click = new MouseEvent('click', {
+                    gesture.type = 'long-tap'
-                        'clientX': gesture.viewport_x, 'clientY':gesture.viewport_y, 'buttons': 1,
+                    get_boss().handle_gesture(gesture)
-                        'view':window.self, 'bubbles': True, 'cancelable': True,
-                    })
-                    elem = document.elementFromPoint(fake_click.clientX, fake_click.clientY)
-                    if elem:
-                        elem.dispatchEvent(fake_click)
                 return
             if not gesture.active:
                 if self.for_side_margin or not tap_on_link(gesture):

src/pyj/read_book/view.pyj

@@ -150,6 +150,7 @@ class View:
             'error': self.on_iframe_error,
             'next_spine_item': self.on_next_spine_item,
             'next_section': self.on_next_section,
+            'lookup_word': self.on_lookup_word,
             'goto_doc_boundary': def(data): self.goto_doc_boundary(data.start);,
             'scroll_to_anchor': self.on_scroll_to_anchor,
             'update_cfi': self.on_update_cfi,
@@ -174,6 +175,9 @@ class View:
     def iframe(self):
         return self.iframe_wrapper.iframe
 
+    def on_lookup_word(self, data):
+        self.overlay.show_word_actions(data.word)
+
     def left_margin_clicked(self, event):
         if event.button is 0:
             event.preventDefault(), event.stopPropagation()

src/pyj/read_book/word_actions.pyj

@@ -0,0 +1,26 @@
+# vim:fileencoding=utf-8
+# License: GPL v3 Copyright: 2018, Kovid Goyal <kovid at kovidgoyal.net>
+from __python__ import bound_methods, hash_literals
+
+from gettext import gettext as _
+from book_list.item_list import create_item, create_item_list
+
+
+def lookup(close_panel_func, url):
+    close_panel_func()
+    window.open(url, '_blank')
+
+
+def lookup_items(word, close_panel_func):
+    eword = encodeURIComponent(word)
+    items = [
+        create_item(_('Lookup in Google dictionary'), lookup.bind(word, close_panel_func, f'https://google.com/search?q=define:{eword}')),
+        create_item(_('Lookup in Wordnik'), lookup.bind(word, close_panel_func, f'https://www.wordnik.com/words/{eword}')),
+        create_item(_('Search the internet'), lookup.bind(word, close_panel_func, f'https://google.com/search?q={eword}')),
+    ]
+    return items
+
+
+def create_word_actions_panel(container, word, close_panel_func):
+    list_container = container.lastChild
+    create_item_list(list_container, lookup_items(word, close_panel_func))

src/pyj/select.pyj

@@ -0,0 +1,44 @@
+# vim:fileencoding=utf-8
+# License: GPL v3 Copyright: 2018, Kovid Goyal <kovid at kovidgoyal.net>
+from __python__ import bound_methods, hash_literals
+
+
+def range_from_point(x, y):
+    r = None
+    if document.caretPositionFromPoint:
+        p = document.caretPositionFromPoint(x, y)
+        if p:
+            r = document.createRange()
+            r.setStart(p.offsetNode, p.offset)
+            r.collapse(True)
+    elif document.caretRangeFromPoint:
+        r = document.caretRangeFromPoint(x, y)
+    return r
+
+
+def word_boundary_regex():
+    ans = word_boundary_regex.ans
+    if ans is undefined:
+        ans = word_boundary_regex.ans = /[\s!-#%-\x2A,-/:;\x3F@\x5B-\x5D_\x7B}\u00A1\u00A7\u00AB\u00B6\u00B7\u00BB\u00BF\u037E\u0387\u055A-\u055F\u0589\u058A\u05BE\u05C0\u05C3\u05C6\u05F3\u05F4\u0609\u060A\u060C\u060D\u061B\u061E\u061F\u066A-\u066D\u06D4\u0700-\u070D\u07F7-\u07F9\u0830-\u083E\u085E\u0964\u0965\u0970\u0AF0\u0DF4\u0E4F\u0E5A\u0E5B\u0F04-\u0F12\u0F14\u0F3A-\u0F3D\u0F85\u0FD0-\u0FD4\u0FD9\u0FDA\u104A-\u104F\u10FB\u1360-\u1368\u1400\u166D\u166E\u169B\u169C\u16EB-\u16ED\u1735\u1736\u17D4-\u17D6\u17D8-\u17DA\u1800-\u180A\u1944\u1945\u1A1E\u1A1F\u1AA0-\u1AA6\u1AA8-\u1AAD\u1B5A-\u1B60\u1BFC-\u1BFF\u1C3B-\u1C3F\u1C7E\u1C7F\u1CC0-\u1CC7\u1CD3\u2010-\u2027\u2030-\u2043\u2045-\u2051\u2053-\u205E\u207D\u207E\u208D\u208E\u2329\u232A\u2768-\u2775\u27C5\u27C6\u27E6-\u27EF\u2983-\u2998\u29D8-\u29DB\u29FC\u29FD\u2CF9-\u2CFC\u2CFE\u2CFF\u2D70\u2E00-\u2E2E\u2E30-\u2E3B\u3001-\u3003\u3008-\u3011\u3014-\u301F\u3030\u303D\u30A0\u30FB\uA4FE\uA4FF\uA60D-\uA60F\uA673\uA67E\uA6F2-\uA6F7\uA874-\uA877\uA8CE\uA8CF\uA8F8-\uA8FA\uA92E\uA92F\uA95F\uA9C1-\uA9CD\uA9DE\uA9DF\uAA5C-\uAA5F\uAADE\uAADF\uAAF0\uAAF1\uABEB\uFD3E\uFD3F\uFE10-\uFE19\uFE30-\uFE52\uFE54-\uFE61\uFE63\uFE68\uFE6A\uFE6B\uFF01-\uFF03\uFF05-\uFF0A\uFF0C-\uFF0F\uFF1A\uFF1B\uFF1F\uFF20\uFF3B-\uFF3D\uFF3F\uFF5B\uFF5D\uFF5F-\uFF65]/
+    return ans
+
+
+def expand_offset_to_word(string, offset):
+    start = offset
+    pat = word_boundary_regex()
+    while start >= 1 and not pat.test(string.charAt(start - 1)):
+        start -= 1
+    end, sz = offset, string.length
+    while end < sz and not pat.test(string.charAt(end)):
+        end += 1
+    return {'word': string[start:end], 'start': start, 'end': end}
+
+
+def word_at_point(x, y):
+    r = range_from_point(x, y)
+    if r and r.startContainer.nodeType is 3:
+        word_info = expand_offset_to_word(r.startContainer.data, r.startOffset)
+        if word_info.word:
+            r.setStart(r.startContainer, word_info.start)
+            r.setEnd(r.startContainer, word_info.end)
+            return r