LightListManager User GuideCapturing Pictures of Lights and Links to Web Pages
I suspect this feature of the program will have little or no value, but I added it anyway. Many of the Light List entries are very distinctive appearing structures (not very well described by the Structure field) and have significant historical value. Also there are many special purpose lights that have unique appearances. Often on a passage I have noticed one of the those special purpose lights on the chart and wonder what it looks like. So I added this feature to allow the user to capture images of those lights and links to webpages on the light. Then have the program display the images along with the Light List data.
Figure 1 shows the form used to capture this links for a selected Light List entry. The form is activated by right clicking on an entry in the main form and selecting the Pictures and Links pop-up menu item. In this case the links for the Smith Point Lighthouse at the mouth of the Potomac River have been displayed. There are three textboxes on the form to capture Links pertaining to this light.
- Picture URI: A link to a picture of this light on the Web.
- Picture File: The full name of a graphc file (jpg, BMP, png or GIF) on the user PC.
- Webpage URI: A link to a webpage that contains useful or interesting information on the Light
I have captured a jpg of the Smith Point Lighthouse that I took many years ago. I've also captured a link to a Wikipedia page on this light. Wikipedia provides pages on most of the significant lighthouses in the U.S. and other countries. I did not capture a link to a picture of this light on the web as I provided the picture from my own system. Unless the web source provides a picture with no restrictions, this link is of little value. I have been able to capture useful pictures from WikiPedia for many light houses and from NOAA for their weather data buoys.
The capture form is fairly crude. The web links are entered by copying the URI from a browser and pasting it into the text box on the form. The capture of the picture file is done via a file open dialog box, but the file name can also be entered by a paste or typing. If this program feature turns out to be more useful than I expect I will enhance this form with a better tool to capture the links.
When a link is pasted into either of the URI textboxes, the Show button next to the text box comes active. Clicking that button will display whatever that link points to in the default browser. The Download button next to the Picture URI textbox will cause the program to attempt a download of the linked picture. With a successful download, the program will attempt to convert the file to a bitmap image so it can be displayed. This is where most of the pictures on the web will fail because of protections embedded in the file. The picture can still be used as link to the image as it exists on the host webpage, but it cannot be displayed by the program. Files that can be converted to a Bitmap (i.e., unprotected images) will be saved by the program and the local link to the file inserted into the Picture File textbox. Those pictures can be displayed by the program without an Internet connection.
Entering a file name in the Picture File textbox will display that file in the box in the lower left corner of the form. When any of those three textboxes are changed the Save Links button is activated. Clicking that button saves the contents of those textboxes to a table internal to the form. When all of the links for the lights in the comboboxes at the top of the form have been captured, click the Done button to save the changes and exit the form. Clicking the Cancel button will also close the form, but any links that have not been saved are discarded. When the LightListManager program is terminated all of the changes to the picture and links collections are saved to the Pics.xml file and restored when program is next run.
Displaying the Captured Links
Other than the capture form, currently only the Light Details form provides a means to display the links.
Figure 2 shows the Light Details Form with the captured links at the bottom of the form. Any of these links can be displayed by clicking the Show button next to the textboxes.
In Figure 3 I have clicked the Show button next to the Picture File link and the captured photo is displayed.
In Figure 4 I have clicked the Show button next to the Webpage Link and my browser has openned on the Wikipedia page on the Cove Point Lighthouse.
In Figure 5 I have clicked the Show button next to the Picture on the Web link for a NOAA weather buoy and my browser has displayed the picture from the NOAA website. In this case NOAA does not provide any restrictions on copying the graphic and the program has downloaded the captured image file as a Picture File link as well.
The links are stored in xml files (one for each Volume/District) in the Pics folder under the main light list folder. The contents of the Links xml file for a Volume/District is loaded into memory whenever the Light List xml file for that Volume/District is loaded. The data in the Links file is loaded into a program table. When the program is terminated the contents of each such table is written back to the Links xml files. All captured picture files are copied to the Pics folder under the main folder. The original picture file is not moved from its existing location, nor is it modified by the program. As with all bookmarked links on the web, they are subject to becoming invalid due to changes to the host website.
To flag those Light List entries for which a picture has been linked, "Pic" has been added to the LLNR field of the main display. This feature is not depicted by any of the figures in this section of the User Guide as it was implemented after these screen images were captured.
Using My Pictures and Links
In the process of developing this feature I started to collect a number of pictures and links for many lights and lighthouses. Even though I haven't found any real use for the feature I decided to implement a backup capability so I wouldn't have to rebuild all those links the next time my PC decides to give up the ghost. All the picture files and links are stored in the Pics folder under the main Light List folder. I now save a compressed copy of that folder on my website in the same folder as the LightListManager program files.
To provide user access to these files and links I've implemented a download menu item under the Help menu. This menu item will download the compressed contents of my Pics folder, decompress it and merge those files and links with whatever links and files are in the existing Pics folder. So a user can merge my Pics folder contents with theirs. The merge process will not replace any of the existing contents. If a picture file exists on the user's systems for one of the lights in my folder, my content for that light will be discarded.
So this provides a means for users to have access to whatever picture and links I have captured now and in the future. The user still has to provide a backup/recovery capability for the user's pictures and links, just like for any other files on the user's system.
Limitations on This Program Feature
In collecting these pictures (mostly from WikiPedia and U.S. Government sites I've been careful to not use any pictures that are copywrite protected or designated. However; just because there is no protectdion or designation with or in the graphic file does not mean there are no restrictions on its use. If I learn that the owner of the copywrite on a file does wish to restrict the use of the file, I will remove it from the download file. I may in the future have to implement a means to delete it from the users content as well.
Also this feature is not used by the Light Characteristic display form, which uses a picture of the Point No Point light to animate a light characteristic. So you can capture a great picture of a lighthouse, but the program will still use the picture of Point No Point to display the characteristic. That probably will never change regardless of how useful this feature might otherwise become.