I would respectfully offer that it should be:
1) automatic,
2) optional (you have to consciously set a switch), and
3) when you set the switch, you get a warning of the perils of using the function.
The beauty of it is that, if Pleco is camping in Dictionary mode while you use the iPhone to do other things, you immediately (just by quickly task switching) can get in and start writing - no nonsense - where you can then:
1) look up words and/or
2) start immediately writing sentences (who would want to use the built in HWR if you have Pleco's?? its just easier and I get to two finger tap to move to the next character or delete...

)
3) never have to leave dictionary mode (which is good for the next time you need to run to Pleco when using another program).
4) and (I think), it has the advantage of allowing someone to just write into the Dictionary (e.g., throw them the phone and let them write) and if you really want to look at the sentence in more detail, you can flip to the reader without having to do anything. It will already be in the pasteboard, ready to be reviewed.
I do no not want to have to switch to Dictionary mode, then over to some editor mode, then hit the wrong button, then yada yada, and when all is said and done, go back to dictionary mode, etc. Done the way I propose, I do not have to do any of that.
I would agree that there is some risk. But the risk in the case of the pasteboard is there anyway. If someone switches out of Pleco to some other program, that information is already at risk (email, web browsing, and any other program where you might cut and paste). I run into this from time to time now with the way that I use Pleco's Reader and do other stuff on the iPhone, and its not that bad. In fact, when you recut and switch back Pleco, Pleco immediately resets back to the reader, re-enters pasteboard, and I'm back up and running.
Maybe Pleco would need to so some check to see if the Pasteboard has changed since writing (and if not, it does not throw the user to the Reader in Pasteboard mode) upon next re-entry into Pleco via application switching.
Anyway, long story short, I do think there is value with the approach.
EDIT: Related - Maybe this is some new input mode... Along the same lines, using HWR, I can stack up Hanzi for input in this way. However, if I switch to Pinyin Input, It does not let me enter in continuous converted Hanzi. So I get to Pleco Dictionary, and I start typing in Pinyin, see the right word, then want to type the next utilizing Pinyin (but selecting Hanzi. This is different than the Pinyin input where NO definition is provided. In this case the entry mode would allow you to type in the Pinyin and it would show the definitions underneath like the current input method in Pleco for the dictionary using Pinyin. However, similar to HWR, characters would be brought up underneath (with their definitions). Similar to HWR, the user could two-finger tap to accept the first one, could press a second. But rather than bringing up the dictionary for that entry, it would just put the Hanzi in the entry line. In this way, you could build sentences.
EDIT: Unrelated - If someone has a jailbroken iPhone, I found a program that works really well, allowing the user NOT to have a to use the home key for switching apps - called "quickdo" (used to be called "mquickdo"). So I never have to use the home button to switch applications. Saves the home button and allows you do some other quick-launch stuff.
mikelove said:
How about using the built-in text editing function to compose the text you want to copy over - does that help matters any? I'm somewhat wary of this automatic pasteboard overwrite, since it would be easy to forget you'd turned it on and lose some important bit of material in the pasteboard - I think in general this would be better done by a separate / quick-input-optimized version of that text editor screen with an easy button to copy the results to the pasteboard.