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Diffstat (limited to 'Lib/Para.py')
| -rw-r--r-- | Lib/Para.py | 408 |
1 files changed, 408 insertions, 0 deletions
diff --git a/Lib/Para.py b/Lib/Para.py new file mode 100644 index 0000000..6a7057d --- /dev/null +++ b/Lib/Para.py @@ -0,0 +1,408 @@ +# Text formatting abstractions + + +# Oft-used type object +Int = type(0) + + +# Represent a paragraph. This is a list of words with associated +# font and size information, plus indents and justification for the +# entire paragraph. +# Once the words have been added to a paragraph, it can be laid out +# for different line widths. Once laid out, it can be rendered at +# different screen locations. Once rendered, it can be queried +# for mouse hits, and parts of the text can be highlighted +class Para: + # + def __init__(self): + self.words = [] # The words + self.just = 'l' # Justification: 'l', 'r', 'lr' or 'c' + self.indent_left = self.indent_right = self.indent_hang = 0 + # Final lay-out parameters, may change + self.left = self.top = self.right = self.bottom = \ + self.width = self.height = self.lines = None + # + # Add a word, computing size information for it. + # Words may also be added manually by appending to self.words + # Each word should be a 7-tuple: + # (font, text, width, space, stretch, ascent, descent) + def addword(self, d, font, text, space, stretch): + if font <> None: + d.setfont(font) + width = d.textwidth(text) + ascent = d.baseline() + descent = d.lineheight() - ascent + spw = d.textwidth(' ') + space = space * spw + stretch = stretch * spw + tuple = (font, text, width, space, stretch, ascent, descent) + self.words.append(tuple) + # + # Hooks to begin and end anchors -- insert numbers in the word list! + def bgn_anchor(self, id): + self.words.append(id) + # + def end_anchor(self, id): + self.words.append(0) + # + # Return the total length (width) of the text added so far, in pixels + def getlength(self): + total = 0 + for word in self.words: + if type(word) <> Int: + total = total + word[2] + word[3] + return total + # + # Tab to a given position (relative to the current left indent): + # remove all stretch, add fixed space up to the new indent. + # If the current position is already beying the tab stop, + # don't add any new space (but still remove the stretch) + def tabto(self, tab): + total = 0 + as, de = 1, 0 + for i in range(len(self.words)): + word = self.words[i] + if type(word) == Int: continue + fo, te, wi, sp, st, as, de = word + self.words[i] = fo, te, wi, sp, 0, as, de + total = total + wi + sp + if total < tab: + self.words.append(None, '', 0, tab-total, 0, as, de) + # + # Make a hanging tag: tab to hang, increment indent_left by hang, + # and reset indent_hang to -hang + def makehangingtag(self, hang): + self.tabto(hang) + self.indent_left = self.indent_left + hang + self.indent_hang = -hang + # + # Decide where the line breaks will be given some screen width + def layout(self, linewidth): + self.width = linewidth + height = 0 + self.lines = lines = [] + avail1 = self.width - self.indent_left - self.indent_right + avail = avail1 - self.indent_hang + words = self.words + i = 0 + n = len(words) + lastfont = None + while i < n: + firstfont = lastfont + charcount = 0 + width = 0 + stretch = 0 + ascent = 0 + descent = 0 + lsp = 0 + j = i + while i < n: + word = words[i] + if type(word) == Int: + if word > 0 and width >= avail: + break + i = i+1 + continue + fo, te, wi, sp, st, as, de = word + if width + wi > avail and width > 0 and wi > 0: + break + if fo <> None: + lastfont = fo + if width == 0: + firstfont = fo + charcount = charcount + len(te) + (sp > 0) + width = width + wi + sp + lsp = sp + stretch = stretch + st + lst = st + ascent = max(ascent, as) + descent = max(descent, de) + i = i+1 + while i > j and type(words[i-1]) == Int and \ + words[i-1] > 0: i = i-1 + width = width - lsp + if i < n: + stretch = stretch - lst + else: + stretch = 0 + tuple = i-j, firstfont, charcount, width, stretch, \ + ascent, descent + lines.append(tuple) + height = height + ascent + descent + avail = avail1 + self.height = height + # + # Call a function for all words in a line + def visit(self, wordfunc, anchorfunc): + avail1 = self.width - self.indent_left - self.indent_right + avail = avail1 - self.indent_hang + v = self.top + i = 0 + for tuple in self.lines: + wordcount, firstfont, charcount, width, stretch, \ + ascent, descent = tuple + h = self.left + self.indent_left + if i == 0: h = h + self.indent_hang + extra = 0 + if self.just == 'r': h = h + avail - width + elif self.just == 'c': h = h + (avail - width) / 2 + elif self.just == 'lr' and stretch > 0: + extra = avail - width + v2 = v + ascent + descent + for j in range(i, i+wordcount): + word = self.words[j] + if type(word) == Int: + ok = anchorfunc(self, tuple, word, \ + h, v) + if ok <> None: return ok + continue + fo, te, wi, sp, st, as, de = word + if extra > 0 and stretch > 0: + ex = extra * st / stretch + extra = extra - ex + stretch = stretch - st + else: + ex = 0 + h2 = h + wi + sp + ex + ok = wordfunc(self, tuple, word, h, v, \ + h2, v2, (j==i), (j==i+wordcount-1)) + if ok <> None: return ok + h = h2 + v = v2 + i = i + wordcount + avail = avail1 + # + # Render a paragraph in "drawing object" d, using the rectangle + # given by (left, top, right) with an unspecified bottom. + # Return the computed bottom of the text. + def render(self, d, left, top, right): + if self.width <> right-left: + self.layout(right-left) + self.left = left + self.top = top + self.right = right + self.bottom = self.top + self.height + self.anchorid = 0 + try: + self.d = d + self.visit(self.__class__._renderword, \ + self.__class__._renderanchor) + finally: + self.d = None + return self.bottom + # + def _renderword(self, tuple, word, h, v, h2, v2, isfirst, islast): + if word[0] <> None: self.d.setfont(word[0]) + baseline = v + tuple[5] + self.d.text((h, baseline - word[5]), word[1]) + if self.anchorid > 0: + self.d.line((h, baseline+2), (h2, baseline+2)) + # + def _renderanchor(self, tuple, word, h, v): + self.anchorid = word + # + # Return which anchor(s) was hit by the mouse + def hitcheck(self, mouseh, mousev): + self.mouseh = mouseh + self.mousev = mousev + self.anchorid = 0 + self.hits = [] + self.visit(self.__class__._hitcheckword, \ + self.__class__._hitcheckanchor) + return self.hits + # + def _hitcheckword(self, tuple, word, h, v, h2, v2, isfirst, islast): + if self.anchorid > 0 and h <= self.mouseh <= h2 and \ + v <= self.mousev <= v2: + self.hits.append(self.anchorid) + # + def _hitcheckanchor(self, tuple, word, h, v): + self.anchorid = word + # + # Return whether the given anchor id is present + def hasanchor(self, id): + return id in self.words or -id in self.words + # + # Extract the raw text from the word list, substituting one space + # for non-empty inter-word space, and terminating with '\n' + def extract(self): + text = '' + for w in self.words: + if type(w) <> Int: + word = w[1] + if w[3]: word = word + ' ' + text = text + word + return text + '\n' + # + # Return which character position was hit by the mouse, as + # an offset in the entire text as returned by extract(). + # Return None if the mouse was not in this paragraph + def whereis(self, d, mouseh, mousev): + if mousev < self.top or mousev > self.bottom: + return None + self.mouseh = mouseh + self.mousev = mousev + self.lastfont = None + self.charcount = 0 + try: + self.d = d + return self.visit(self.__class__._whereisword, \ + self.__class__._whereisanchor) + finally: + self.d = None + # + def _whereisword(self, tuple, word, h1, v1, h2, v2, isfirst, islast): + fo, te, wi, sp, st, as, de = word + if fo <> None: self.lastfont = fo + h = h1 + if isfirst: h1 = 0 + if islast: h2 = 999999 + if not (v1 <= self.mousev <= v2 and h1 <= self.mouseh <= h2): + self.charcount = self.charcount + len(te) + (sp > 0) + return + if self.lastfont <> None: + self.d.setfont(self.lastfont) + cc = 0 + for c in te: + cw = self.d.textwidth(c) + if self.mouseh <= h + cw/2: + return self.charcount + cc + cc = cc+1 + h = h+cw + self.charcount = self.charcount + cc + if self.mouseh <= (h+h2) / 2: + return self.charcount + else: + return self.charcount + 1 + # + def _whereisanchor(self, tuple, word, h, v): + pass + # + # Return screen position corresponding to position in paragraph. + # Return tuple (h, vtop, vbaseline, vbottom). + # This is more or less the inverse of whereis() + def screenpos(self, d, pos): + if pos < 0: + ascent, descent = self.lines[0][5:7] + return self.left, self.top, self.top + ascent, \ + self.top + ascent + descent + self.pos = pos + self.lastfont = None + try: + self.d = d + ok = self.visit(self.__class__._screenposword, \ + self.__class__._screenposanchor) + finally: + self.d = None + if ok == None: + ascent, descent = self.lines[-1][5:7] + ok = self.right, self.bottom - ascent - descent, \ + self.bottom - descent, self.bottom + return ok + # + def _screenposword(self, tuple, word, h1, v1, h2, v2, isfirst, islast): + fo, te, wi, sp, st, as, de = word + if fo <> None: self.lastfont = fo + cc = len(te) + (sp > 0) + if self.pos > cc: + self.pos = self.pos - cc + return + if self.pos < cc: + self.d.setfont(self.lastfont) + h = h1 + self.d.textwidth(te[:self.pos]) + else: + h = h2 + ascent, descent = tuple[5:7] + return h, v1, v1+ascent, v2 + # + def _screenposanchor(self, tuple, word, h, v): + pass + # + # Invert the stretch of text between pos1 and pos2. + # If pos1 is None, the beginning is implied; + # if pos2 is None, the end is implied. + # Undoes its own effect when called again with the same arguments + def invert(self, d, pos1, pos2): + if pos1 == None: + pos1 = self.left, self.top, self.top, self.top + else: + pos1 = self.screenpos(d, pos1) + if pos2 == None: + pos2 = self.right, self.bottom,self.bottom,self.bottom + else: + pos2 = self.screenpos(d, pos2) + h1, top1, baseline1, bottom1 = pos1 + h2, top2, baseline2, bottom2 = pos2 + if bottom1 <= top2: + d.invert((h1, top1), (self.right, bottom1)) + h1 = self.left + if bottom1 < top2: + d.invert((h1, bottom1), (self.right, top2)) + top1, bottom1 = top2, bottom2 + d.invert((h1, top1), (h2, bottom2)) + + +# Test class Para +# XXX This was last used on the Mac, hence the weird fonts... +def test(): + import stdwin + from stdwinevents import * + words = 'The', 'quick', 'brown', 'fox', 'jumps', 'over', \ + 'the', 'lazy', 'dog.' + paralist = [] + for just in 'l', 'r', 'lr', 'c': + p = Para() + p.just = just + p.addword(stdwin, ('New York', 'p', 12), words[0], 1, 1) + for word in words[1:-1]: + p.addword(stdwin, None, word, 1, 1) + p.addword(stdwin, None, words[-1], 2, 4) + p.addword(stdwin, ('New York', 'b', 18), 'Bye!', 0, 0) + p.addword(stdwin, ('New York', 'p', 10), 'Bye!', 0, 0) + paralist.append(p) + window = stdwin.open('Para.test()') + start = stop = selpara = None + while 1: + etype, win, detail = stdwin.getevent() + if etype == WE_CLOSE: + break + if etype == WE_SIZE: + window.change((0, 0), (1000, 1000)) + if etype == WE_DRAW: + width, height = window.getwinsize() + d = None + try: + d = window.begindrawing() + d.cliprect(detail) + d.erase(detail) + v = 0 + for p in paralist: + v = p.render(d, 0, v, width) + if p == selpara and \ + start <> None and stop <> None: + p.invert(d, start, stop) + finally: + if d: d.close() + if etype == WE_MOUSE_DOWN: + if selpara and start <> None and stop <> None: + d = window.begindrawing() + selpara.invert(d, start, stop) + d.close() + start = stop = selpara = None + mouseh, mousev = detail[0] + for p in paralist: + start = p.whereis(stdwin, mouseh, mousev) + if start <> None: + selpara = p + break + if etype == WE_MOUSE_UP and start <> None and selpara: + mouseh, mousev = detail[0] + stop = selpara.whereis(stdwin, mouseh, mousev) + if stop == None: start = selpara = None + else: + if start > stop: + start, stop = stop, start + d = window.begindrawing() + selpara.invert(d, start, stop) + d.close() + window.close() |