%Doc-1.0 \documentstyle{slides} \begin{document} {\align{center}\float{}{\pagenumber{00}}%383.04 -639.12 -2 \size{52}Glyphs:\\ Flyweight Objects\\ for User Interfaces\size{18}\bigskip \size{36}Paul Calder\size{18}\bigskip \size{24}Computer Systems Laboratory\\ Stanford University\\ Stanford, California 94305\size{18}\bigskip \font{Courier}calder@interviews.stanford.edu }\newpage {\size{36}The problem}\bigskip {\size{24}Objects are good ...}\smallskip \quad data as well as commands \quad users think objects \quad smallest components should be objects\medskip {\size{24}... but current toolkits fall short}\smallskip \quad gap between objects and widgets \quad cannot build views of data \newpage {\size{36}The experiment{\size{18}% % \figure{% \psfig{figure=doc.ps,width=5in}% %34.56 -328.32 2 }% % }}\newpage {\size{36}The experiment ...}\bigskip {\size{24}Build a document editor}\smallskip \quad each character is an object \quad graphics as well as text \quad papers, thesis, slides\medskip {\size{24}Why a document editor?}\smallskip \quad familar---well understood medium \quad high expectations---looks good, goes fast \quad severe test---100,000 objects\medskip {\size{24}More than just document editors}\smallskip \quad views of application data \quad smallest components are objects \newpage {\size{36}Glyphs}\bigskip {\size{24}Glyphs just define appearance}\smallskip \quad primtivies---line, circle, character, image \quad composites---box, deck\medskip {\size{24}Glyphs are simple}\smallskip \quad \begin{tabular}{|l|l|} \hline Task& Methods\\ \hline geometry& request,\ allocate\\ appearance& draw,\ pick\\ structure& insert,\ remove,\ change\\ \hline \end{tabular}% \medskip {\size{24}Glyphs are cheap}\smallskip \quad {\it much} cheaper than widgets\medskip {\size{24}Toolkit must include more}\smallskip \quad handlers---event distribution, event mapping \quad interactors---buttons, menus, scrollers \newpage {\size{36}A text view ...}\bigskip \quad % \psfig{figure=objects.ips}% \medskip {\size{24}View structure reflects text structure}\smallskip \quad glyph per character \quad composite glyph per line \newpage {\size{36}TextView code}\bigskip {\tt TextView::TextView\ (FILE*\ file)\ \{\ \ \ TBBox*\ page\ =\ new\ TBBox();\ \ \ LRBox*\ line\ =\ new\ LRBox();\ \ \ int\ c;\ \ \ while\ ((c\ =\ getc(file))\ !=\ EOF)\ \{\ \ \ \ \ if\ (c\ ==\ '\backslash n')\ \{\ \ \ \ \ \ \ page->append(line);\ \ \ \ \ \ \ line\ =\ new\ LRBox();\ \ \ \ \ \}\ else\ \{\ \ \ \ \ \ \ line->append(new\ Character(c));\ \ \ \ \ \}\ \ \ \}\ \ \ body(page)\ \}\ }\newpage {\size{36}... with multiple fonts ...}\bigskip \quad % \psfig{figure=euctext.ps,width=5.5in}% \medskip {\size{24}Same simple structure but ...}\smallskip \quad ASCII characters use ASCII-encoded font \quad Kanji characters use JIS-encoded font \newpage {\size{36}EUC TextView Code}\bigskip {\tt Font*\ kf;\ Font*\ af;\ \ while\ ((c\ =\ getc(file))\ !=\ EOF)\ \{\ \ \ if\ (c\ ==\ '\backslash n')\ \{\ \ \ \ \ page->append(line);\ \ \ \ \ line\ =\ new\ LRBox();\ +\ \}\ else\ if\ (!isascii(c))\ \{\ +\ \ \ line->append(\ \ \ \ \ \ \ new\ Character(\ \ \ \ \ \ \ \ \ tojis(c,\ getc(file)),\ kf\ \ \ \ \ \ \ )\ \ \ \ \ );\ \ \ \}\ else\ \{\ \ \ \ \ line->append(new\ Character(c,\ af));\ \ \ \}\ \}\ }\newpage {\size{36}... and formatting}\bigskip \quad % \psfig{figure=fancytext.cut.ps,width=5.5in}% \medskip {\size{24}High-level help from a toolkit}\smallskip \quad line and column breaking \quad hyphenation \newpage {\size{36}Formatted TextView code}\bigskip {\tt Composition*\ page\ =\ new\ LRComposition(\ \ \ new\ TBBox(),\ new\ TeXCompositor(),\ \ \ nil,\ width\ );\ \ while\ ((c\ =\ getc(file))\ !=\ EOF)\ \{\ \ \ if\ (c\ ==\ '\backslash n')\ \{\ \ \ \ \ page->append(\ \ \ \ \ \ \ new\ Discretionary(\ \ \ \ \ \ \ \ \ PenaltyGood,\ new\ HGlue(fil),\ \ \ \ \ \ \ \ \ new\ HGlue(0,\ fil),\ nil,\ nil\ \ \ \ \ \ \ )\ \ \ \ \ );\ \ \ \}\ else\ if\ (c\ ==\ '\ ')\ \{\ \ \ \ \ page->append(\ \ \ \ \ \ \ new\ Discretionary(\ \ \ \ \ \ \ \ \ 0,\ new\ Character('\ '),\ \ \ \ \ \ \ \ \ new\ HGlue(0,\ 0),\ nil,\ nil\ \ \ \ \ \ \ )\ \ \ \ \ );\ \ \ \}\ else\ \{\ \ \ \ \ page->append(new\ Character(c));\ \ \ \}\ \}\ }\newpage {\size{36}Implementation}\bigskip {\size{24}A dynamic protocol ...}\smallskip \quad pass state rather than store it \quad Character::draw(Canvas*, Paint\&, allocation\&)\medskip {\size{24}... means small objects ...}\smallskip \quad objects needn't store graphics state \quad Character need only store character code\medskip {\size{24}... and fewer instances}\smallskip \quad sharable objects \quad one instance of Character(`a') per document \newpage {\size{36}Performance}\bigskip {\size{24}Drawing speed}\smallskip \quad \begin{tabular}{|l|r|r|} \hline Page\ type& Draw& Format\\ \hline small& 0.07& 0.12\\ average& 0.11& 0.20\\ large& 0.25& 0.37\\ \hline \end{tabular}% \quad Seconds per page on a DECstation 3100\medskip {\size{24}Process size}\smallskip \quad \begin{tabular}{|l|r|} \hline Document& Memory\ usage\\ \hline small& 1500\\ medium& 2300\\ large& 4000\\ \hline \end{tabular}% \quad Total Kbytes allocated \newpage {\size{36}Comparisons}\bigskip {\size{24}Object size}\smallskip \quad \begin{tabular}{|l|l|r|} \hline Toolkit& Object& Size\\ \hline Athena\ Widgets& Simple& 132\\ Andrew\ Toolkit& view& 44\\ ET++& VObject& 32\\ Extended\ InterViews& Glyph& 8\\ \hline \end{tabular}% \quad Sizes of base objects in bytes\medskip {\size{24}Code size}\smallskip \quad \begin{tabular}{|l|r|r|} \hline Toolkit& Label& TextView\\ \hline Athena\ Widgets& 500& 2000\\ Andrew\ Toolkit& 300& 3000\\ ET++& 500& 2000\\ Extended\ InterViews& 10& 20\\ \hline \end{tabular}% \quad Lines of code for views \newpage {\size{36}Status}\bigskip {\size{24}Prototype toolkit}\smallskip \quad glyph---primitives, decorators, composites \quad layout---tiling, aligning \quad compositor---array, split, fill (optimum fit) \quad sensor---input interest \quad handler---interactors\medskip {\size{24}Document editor}\smallskip \quad basic editing (text, graphics, tables) \quad figure plowing \quad 5000 lines of code \quad papers, slides, thesis\medskip {\size{24}Merge into InterViews} \newpage {\size{36}Conclusion}\bigskip {\size{24}Toolkits can help build views of data}\smallskip \quad not just command interface\medskip {\size{24}Dynamic protocols for cheap objects}\smallskip \quad think lots of objects\medskip {\size{24}Leverage available technology}\smallskip \quad already beyond interactive threshold % \end{document}