|© 1998 Michael J. Hammel|
Notepads are just TextArea form elements. You can drag these but you have to click on the NotePads title - you can't drag from the textarea or its scrollbar.
News boxes are interesting. You can add HTML tags to the title too, but breaks will cause part of the title to go unnoticed without some font specification. Also there are 4 navigational aides on the 4 corners of the news box. If you place the mouse over the Go aide (upper left corner) the scrolling in the news box increases. On the lower left corner, the Stop aide will slow and eventually stop the scrolling. The Up and Down aides move the news text by small increments.
There is a digital clock which you can set the background color for, but it seems to fill a box around the clock, not the the background of the clock itself. There is also a date widget which is just some colored text of a user-specified size (you can't specify the font, however).Bug: Adding a menu item appeared to lock up the browser. Top reported the application was asleep an using >50% of my 64Mb of memory at that point.
Toolbar items can be added to the toolbar after the toolbar is created. A Toolbar is just another name for a menu bar with icons. Its not obvious, but there are two links in the widget dialog for Toolbars - one for the toolbar itself and right below that is one for adding individual toolbar items (yes, its actually says "Item" but it all looks like one link).
Be careful about adding a Toolbar if you have other items at the top of the page already - you can't move the menu bar and if something is underneath it that item can't be dragged to a new location because the menu will be placed over the other item.Not all widgets are available from the Widgets dialog. The table widget we just mentioned. There is a Channel Widget available from the Channels pull-down menu in the main VDHTML window. I'm not sure what this is for, however. The default URL for the image to use for this widget didn't resolve so I can't show an image of the default here.
Tables are accessible from the Text pull down menu (not from the Widget dialog) because they expect you'll be filling the table with text (although you can place HTML code in them too). Unfortunately, if you specify a table that will be larger than the default VDHMTL Main Window you won't get any scrollbars to access all the rows and/or columns. Worse, you can't resize the Main Window! Moral: use small tables and edit it by hand later.
You can tell the VDHTML has a way to go yet when you realize that there is no way to remove an widget from the preview window. I tried dragging them out of the window but that didn't seem to work. It just seems to move the widget to an offscreen area but leaves it on the page. You can prove this by dragging the default plug-in widget off the bottom of the browser window. When the page reloads you will still get notices about needing a Shockwave plug-in (which for Linux does not exist to my knowledge) even though you thought you removed the widget which had previously required it.And there is no menu option for removing these widgets from the Main Window either.
An interesting side effect showed up when I tried to use a preferences widget, which is just a pop down menu. I then used that menu to select "Reload Page" from within the preview window (this option and two other options were provided as the defaults for this widget). This caused my preview window to load Visual DHTML in the preview window! The page I was working on disappeared! Fortunately, a right mouse click in the preview window brought up the familiar Netscape popup menu from which I could choose "Back" to return to my DHTML page. Similarly, I discovered that I could restart the Visual DHTML application from its Main Window by using the Back option of the Netscape popup menu (ie the menu you get with a right mouse click in a browser window). Note that if you do this and you have a preview window open then the restarted VDHTML will not recognize that window - you'll have to start a new preview window.
This little experiment with using the BACK option also showed another little bug - the menu bar in the real VDHTML window is statically sized, so when VDHTML opened in my larger preview window, the menu bar didn't go all the way across the window. Maybe its not a bug. Its a design intent. I just don't think they meant for VDHTML to be opened in the preview window! After seeing this I tried to resize the Main Window using the window manager handles, except I discovered there were no handles for resizing that window. An old GUI developers trick - if you don't want the user doing something, don't give them the ability to do so. I use it all the time when dealing with resizing windows. Realignment of widgets in Motif is a pain.
DHTML can usually be embedded within any of the widgets since most take either URLs or ordinary text in their configurable options. The text can be DHTML although VDHTML doesn't really make it easy to add this to the text field in the options window.
Bug: If the link is down or very slow there doesn't appear to be a way to tell VDHTML to stop trying to connect to the remote URL. You can't do anything with Netscape until the hosts network address is resolved.
Since no links show up in the status bar like in an ordinary browser window you can't tell when you've place the mouse over a link in either the preview window or the Main window. This is probably a good thing, but in places (like the toolbar widget and item links) it would help.
Don't forget that this tool is creating a DHTML page, which is an ordinary text file. You can save the file to disk and edit it later, so don't fret too much about the lack of configurability in the current release of the VDHTML application. If you do attempt to save your creation you will need to go through one of the Java security dialogs to grant the application (Netscape) to access your local hard disk. I never had to deal with this particular security aspect in the past and it suprised me just a bit. But don't worry - its just the local VDHTML application you're granting access to and it is only for the current session, unless you specify that the browser remember this priviledge by clicking on a toggle in the dialog.
The code VDHTML produces is marginally readable, but don't expect it
to fit nicely inside 80 column wide editor windows! Like the code
produced by the Page Composer, "newline" line breaks are not included in
the HTML text. You can edit this text as easily as any other text
once you get used to the missing newlines.
What is my opinion of its current state.
VDHMTL makes use of Layers and Cascading Style Sheets. These are rather interesting new features for HTML, certainly ones which can add some life to relatively static pages. But the overhead for animating and running scripts within the browser is unclear. My system didn't bog down, but it did have half of its available physical memory used up by the browser while it ran this tool. For now, this is to be expected. Get the application working first, then work on cleaning it up to make it efficient. Not the best development plan, but a common one nonetheless. I expect that much of the improvements in the future will come not from the VDHTML code itself, but in the way the browser handles that code.
As for Visual DHTML itself, it needs some work. The interface is nice but I expect it to change drastically over the next few releases. Most of the widgets don't have nearly all the possible configurable parameters they could have so the Main Window will probably change to accomodate those options. There are lots of bugs and unexpected behaviours in this release, like accidently launching the application in the preview window. It is, in fact, so buggy that I gave up trying to get a screen shot of the available default widgets because I couldn't get them all to cooperate enough so I could position them within a reasonably sized window. And the use of style sheets is not very evident - no font configuration for example.
One final note: on the Netscape page for Visual DHTML is a link
to an Midi-player example from Crescendo that was written with Visual DHTML.
Watch out for the Crescendo sample page! It removes the Netscape
menu bars and using the back button doesn't get them back! I had
to exit Netscape using my window manager Close option and start over.
|© 1998 by Michael J. Hammel|