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Context phrases are defined for each topic in the rtf
source file. The CS Help compiler generates a C++ header file, which contains
literal descriptors created from the context phases. This header file must be
included in the C++ applications, and is used to link each control to the
appropriate topic.
In the rtf
source file the process is:
Create a new line before the topic text in the source rtf file.
Enter a string which describes the context for the particular topic.
Mark the context in Context
style.
Repeat the above for each topic.
Generate the CS Help file and C++ header file.
In a C++ application the process is:
Create the CCoeControl
derived view or control for
each context.
#include the header file from the CS Help compiler.
Overload the
CCoeControl::GetHelpContext(TCoeHelpContext& aContext)
function for the new control. The function should return a
TCoeHelpContext
which contains the UID of the help file and the
literal descriptor for the appropriate help topic context. This is all that is
required to link the control and the appropriate Help topic.
Compile the application.
The three CS Help topics for the Shapes example project have the
context text “This is a circle”, “This is a square” and “This is a
dialog”. When the project is compiled, a header file containing descriptors
for each of these is written to the project's releases
sub-directory.
The descriptor for each context is created by prefixing the context
string with a K, and replacing any spaces with underscores. The C++ comments
are generated from text in context comment
style in the source
rtf
file. A listing of the header file for the shapes
application—Shapes.hlp.hrh
—is given below:
_LIT(KThis_is_a_circle,"This_is_a_circle"); //with a comment (round)
_LIT(KThis_is_a_square,"This_is_a_square"); //with a comment(square)
_LIT(KThis_is_a_dialog,"This_is_a_dialog"); //with a comment(dialog)
Context sensitivity is added to each of the three controls by
overloading their inherited GetHelpContext()
function. When help
is requested, the function for the control which has focus is called, and hence
the appropriate help topic is displayed.
The overload for the square control is shown below:
void CShapesAppViewSquare::GetHelpContext(TCoeHelpContext& aContext) const
{
aContext.iMajor = TUid::Uid(0x01123456);
aContext.iContext = KThis_is_a_square;
}