Screen Hotspots enable the placement of clickable areas over certain patterns that appear on your client screen. The most obvious use is to enable clickable function key definitions that may appear on the bottom rows of the display.
To Manage Hotspot Definitions
Open the SCHSDef.js file in your favourite editor (e.g. Notepad). The LoadHSDefs function initialises hotspots the first time a browser session starts. To specify the area of the screen to convert text to hostpots change the properties in the NewHSDef function call.
NewHSDef("default","= ",7,27,true,2);
The first parameter is to enable multiple keyboard definitions in one browser. This will be set when more than one session and of different terminal types are open in a browser.
The second parameter is a list of characters that must terminate text on the screen for it to be a hotspot. For example, the above example would result in the text "F3=Exit" being converted into a hotspot (a clickable button). The list of characters can be extended to handle more possibilities, for example, the list could be changed to "= :" to also use the colon character.
The third parameter (7) refers to the screen row number to begin hotspot replacement.
The fourth parameter refers to the screen row to stop the hotspot replacement.
The fifth parameter if set to true will extend the hotspot to extend to the following text. For example, if it is set to false then for "F3=Exit", only the "F3" will become a hotspot. If set to true then all the "F3=Exit" will become a hotspot.
The sixth parameter specifies how many blanks should terminate the hotspot. A hotspot will stop after the set number of blanks --or-- one or more blanks where the next string is a defined hotspot.
Following the first line in the hotspot file is a line for each string you want to recognize followed by the keying actions for that text. Each line calls the hsa(text,action) function (hsa=Hot Spot Action).
Note: text to be detected is case sensitive so this may require multiple definitions if the host application displays inconsistent values
For example:
hsa("F1","PF1");
...
hsa("PF1","PF1");
...
hsa("CLEAR","Clear");
hsa("more...","PageDown");
hsa("More...","PageDown");
Performance Notes
The hotspot detection and replacement code runs on the client in the DHTML Javascript code. Most contemporary PC processors have plenty of speed to handle this logic. However, if you have a base of PC's with older, slower processors, you can impact performance of new screen refreshes with excessive numbers of hotspot definitions.
The best way to address any sluggishness that you suspect is hotspot related is to alter the lines where hotspot detection occurs--for example: NewHSDef("default","= ",23,27,true,2); Will only look for hotspot text starting at row 23 instead of the default which is row 7.
