How to use Eclipse's Display View for Debug?

Question

At the link below it explains that the "display view allows you to manipulate live code in a scrapbook type fashion (see Figure 8). To manipulate a variable, simply type the name of the variable in the Display view, and you'll be greeted with a familiar content assist."

http://www.ibm.com/developerworks/library/os-ecbug/

However, I am having trouble getting it to work. I have the view open but all the buttons are disabled. I have tried putting code in the view, selecting code in the view, selecting code in other views, while running and while not running debug, but the only button that is ever enabled on the view is "clear console".

Suggestions on what I am doing wrong?

dimitrisli · Accepted Answer · 2010-12-21T15:17:31.450

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You can view the Display view as a place where you can inspect all sorts of variables and boolean expressions during runtime. While your debugger is frozen on a breakpoint start typing the name of an object variable for instance and you'll get autocomplete functionality as you start calling methods or fields to reach deeper class datastructures. Then when you select/mark the portion you need to inspect or everything, the buttons on the Display view will be clickable. You can always perform the Ctrl+Shift+I shortcut on the selection to view what's the current runtime state of your selection i.e. variable, object, boolean exrepssion etc

edited Dec 21 '10 at 15:17

answered Dec 21 '10 at 14:55

dimitrisli

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I find it especially useful to sys out some values inferred via getters which are not accessible in the Variables view. Saves precious time... Not sure why it is not there by default in Eclipse, it should be ! – Christophe Roussy Apr 24 '15 at 08:55
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Is there any keyboard shortcut for the Display Result/Evaluate button? I find it inconvinient to select, then move the mouse all the way to the right everytime. Note that I don't mean SHIFT+CTRL+I, I mean clicking "J" icon in the view itself. I haven't found a shortcut for that yet. – Jose Cifuentes Sep 09 '16 at 13:46
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Never mind, I found the answer: SHIFT+CTRL+D evaluates the selected text. – Jose Cifuentes Sep 09 '16 at 14:44
How can you execute few Java statements with a small for-loop for example in the Display Window, and then show the result? I tried everything, nothing is working. I am able to display the variables that are defined in the program during the break-point only. Can you help, please? – tarekahf Mar 24 '20 at 17:04

Christophe Roussy · Answer 2 · 2020-02-19T09:54:14.210

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I think this powerful feature should be used way more often.

In the debug perspective: Window -> Show View -> (search for) Display
Put a break point in your code
Trigger the breakpoint by executing this code
Once on the breakpoint go to the Display view
Write some code like myObject.getSomeData();, you can autocomplete (Ctrl+Space)
Select the expression (code) you want to evaluate
Use one of the many display view buttons which should now be enabled
Save some precious time...

Not sure why this view is not there by default, it should be !

edited Feb 19 '20 at 09:54

answered Apr 24 '15 at 09:09

Christophe Roussy

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Also see this article (not mine): https://blog.codecentric.de/en/2013/04/again-10-tips-on-java-debugging-with-eclipse/ – Christophe Roussy Dec 02 '15 at 09:31
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windows > show view > display is what did it for me. Thanks Chris – xandermonkey Aug 01 '16 at 19:07
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thank you, the only actually complete answer. should be the accepted one! – bharal Dec 02 '17 at 16:36
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The Debug perspective is not important for using the Display view. That view can be opened and used in any perspective. – Lii Jun 08 '18 at 07:54
Yes but it seems to be totally unknown to most Eclipse users – Christophe Roussy Jun 28 '18 at 10:40

score 10 · Answer 3 · answered Sep 05 '18 at 00:09

As of Eclipse Photon Release (4.8.0)

This same functionality can be performed inside the the Debug Shell. I do this by:

Make sure I'm at a breakpoint in a Debug execution of some script
Open the Debug Shell
Type in the code that I want to run
Highlight the specific line of code
Use either of the buttons for: Execute Selected Text, or Display Result of Evaluating Selected Text

I'm including this answer because as of 2018, with the Photon Release, I was unable to get the Display view to work in any capacity or to even show up. But I was able to perform the same work through this method.

score 6 · Answer 4 · answered Dec 21 '10 at 15:39

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When you've stopped at a breakpoint, you can write or paste code into the Display view, select it, and press Ctrl+Shift+I to inspect (i.e. evaluate) the selection.

answered Dec 21 '10 at 15:39

Eli Acherkan

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As far as I remember the display view is not there by default (who knows why...) – Christophe Roussy Dec 02 '15 at 09:42

score 4 · Answer 5 · answered Dec 21 '10 at 15:23

It will only work while running in debug, and you can only manipulate variables that are live in the context of the currrent thread, which means that you need to place a breakpoint at (or just after) the point where the variables you want to inspect become active. Whilst you hold on the breakpoint you can use the Display tab to interact (execute code snippets, evaluate etc..) with all the variables that you can see in the Variables tab

How to use Eclipse's Display View for Debug?

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