Add support for hyperlinks in topic page.

You can now click on blue hyperlinks in the topic and it will
jump to that topic. This still needs work and lots more testing.

Signed-off-by: Graeme Geldenhuys <graeme@mastermaths.co.za>

1 files changed, 99 insertions, 0 deletions

diff --git a/src/frm_main.pas b/src/frm_main.pas
index 4dd5b27f..00a91f7d 100644
--- a/src/frm_main.pas
+++ b/src/frm_main.pas
@@ -79,6 +79,7 @@ type
     DisplayedIndex: TStringList; // duplicate of index listbox, for fast case insensitive searching
     CurrentTopic: TTopic; // so we can get easy access to current topic viewed
 
+    procedure   RichViewClickLink(Sender: TRichTextView; Link: string);
     procedure   MainFormShow(Sender: TObject);
     procedure   MainFormDestroy(Sender: TObject);
     procedure   miFileQuitClicked(Sender: TObject);
@@ -131,6 +132,10 @@ type
     procedure   DisplaySelectedIndexTopic;
     procedure   ProcessCommandLineParams;
     procedure   ShowParamHelp;
+    function    FindTopicForLink( Link: THelpLink ): TTopic;
+    function    FindTopicByResourceID( ID: word ): TTopic;
+
+
   public
     constructor Create(AOwner: TComponent); override;
     destructor  Destroy; override;
@@ -169,6 +174,55 @@ begin
   TfpgMessageDialog.Critical('An unexpected error occurred.', E.Message);
 end;
 
+procedure TMainForm.RichViewClickLink(Sender: TRichTextView; Link: string);
+var
+  LinkIndex: integer;
+  lLink: THelpLink;
+  lHelp: THelpFile;
+  i: integer;
+  lTopic: TTopic;
+  lFound: Boolean;
+begin
+  // TODO: process other types of links (external, application etc...) too!
+
+    LinkIndex := StrToInt( Link );
+    lLink := THelpLink(CurrentTopic.Links[LinkIndex]);
+    lTopic := FindTopicForLink(lLink);
+    if lTopic <> nil then
+      DisplayTopic(lTopic);
+    exit;
+
+    lHelp := THelpFile(lLink.HelpFile);
+    lTopic := nil;
+    lFound := False;
+    for i := 0 to CurrentOpenFiles.Count-1 do
+    begin
+      lHelp := THelpFile(CurrentOpenFiles[i]);
+      lTopic := lHelp.Topics[LinkIndex];
+      if lTopic <> nil then
+      begin
+        lFound := True;
+        writeln('Found Topic! ', lTopic.Title);
+        break;
+
+      end;
+      if lFound then
+        break;
+    end;
+    if lTopic <> nil then
+    begin
+      writeln('Displaying topic <', lTopic.Title, '>');
+      DisplayTopic(lTopic);
+    end;
+    //lLink := SourceWindow.Topic.Links[ LinkIndex ];
+    //
+    //PostMsg( Self.Handle,
+    //         WM_FOLLOWLINK,
+    //         longint( Link ),
+    //         longint( SourceWindow ) );
+
+end;
+
 procedure TMainForm.MainFormShow(Sender: TObject);
 begin
   bvlBody.Realign;
@@ -1371,6 +1425,7 @@ Begin
   RichView.AddText(PChar(lText));
 
   tvContents.Selection := tvContents.RootNode.FindSubNode(CurrentTopic, True);
+  tvContents.Invalidate;
 end;
 
 procedure TMainForm.ResetProgress;
@@ -1534,6 +1589,7 @@ begin
     SetPosition(368, 192, 244, 92);
     TabOrder := 2;
     Align := alClient;
+    OnClickLink:=@RichViewClickLink;
   end;
 
   MainMenu := TfpgMenuBar.Create(self);
@@ -1954,6 +2010,8 @@ begin
       ShowParamHelp;
       Exit;
     end
+    else if gCommandLineParams.IsParam('debuglog') then
+      // do nothing
     else
     begin
       showtopic := not gCommandLineParams.IsParam('s');
@@ -1984,10 +2042,51 @@ begin
        + '  -h           Show this help' + le
        + '  -s<<text>     Search for <<text> in open help files' + le
        + '  -t<<id>       Open Topic with ID equal to <<id>' + le
+       + '  -debuglog <<filename> Log information to a file' + le
        + '</tt>'
        ;
   RichView.AddText(PChar(s));
 end;
 
+// Find the target topic for the given link
+function TMainForm.FindTopicForLink(Link: THelpLink): TTopic;
+var
+  HelpFile: THelpFile;
+begin
+  HelpFile := Link.HelpFile as THelpFile;
+  if Link is TFootnoteHelpLink then
+  begin
+    Result := HelpFile.Topics[ TFootnoteHelpLink( Link ).TopicIndex ];
+  end
+  else if Link is TInternalHelpLink then
+  begin
+    Result := HelpFile.Topics[ TInternalHelpLink( Link ).TopicIndex ];
+  end
+  else if Link is THelpLinkByResourceID then
+  begin
+    Result := FindTopicByResourceID( THelpLinkByResourceID( Link ).ResourceID );
+  end
+end;
+
+// Find topic specified by numeric resource ID, in all open files
+function TMainForm.FindTopicByResourceID(ID: word): TTopic;
+var
+  FileIndex: longint;
+  HelpFile: THelpFile;
+begin
+  for FileIndex := 0 to CurrentOpenFiles.Count - 1 do
+  begin
+    HelpFile := THelpFile(CurrentOpenFiles[ id ]);
+
+    Result := HelpFile.FindTopicByResourceID( ID );
+    if Result <> nil then
+      // found
+      exit;
+  end;
+
+  // not found.
+  Result := nil;
+end;
+
 
 end.