Merge lp:~mir-team/mir/ensure-valid-cursor into lp:mir

[Robert Carr]

Ensure the_cursor() is not null.

fixes: lp: #1334010

Ensure the_cursor() is not null.

fixes: lp: #1334010

[Kevin DuBois (kdub)]

From IRC discussion, seems the plan is to remove create_hardware_cursor() in the near future, so I'm okay with allocating in the DefaultServerConfiguration. (as opposed to having nested and android make the null objects)

review: Approve

[Alberto Aguirre (albaguirre)]

Sure

review: Approve

[PS Jenkins bot (ps-jenkins)]

FAILED: Autolanding.
No commit message was specified in the merge proposal. Hit 'Add commit message' on the merge proposal web page or follow the link below. You can approve the merge proposal yourself to rerun.
https://code.launchpad.net/~mir-team/mir/ensure-valid-cursor/+merge/224372/+edit-commit-message

review: Needs Fixing (continuous-integration)

[PS Jenkins bot (ps-jenkins)]

PASSED: Continuous integration, rev:1720
http://jenkins.qa.ubuntu.com/job/mir-team-mir-development-branch-ci/1991/
Executed test runs:
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-android-utopic-i386-build/688
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-clang-utopic-amd64-build/694
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-utopic-touch/688
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-team-mir-development-branch-utopic-amd64-ci/512
        deb: http://jenkins.qa.ubuntu.com/job/mir-team-mir-development-branch-utopic-amd64-ci/512/artifact/work/output/*zip*/output.zip
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-team-mir-development-branch-utopic-armhf-ci/509
        deb: http://jenkins.qa.ubuntu.com/job/mir-team-mir-development-branch-utopic-armhf-ci/509/artifact/work/output/*zip*/output.zip
    SUCCESS: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-builder-utopic-armhf/2031
        deb: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-builder-utopic-armhf/2031/artifact/work/output/*zip*/output.zip
    SUCCESS: http://jenkins.qa.ubuntu.com/job/mir-mediumtests-runner-mako/1864
    SUCCESS: http://s-jenkins.ubuntu-ci:8080/job/touch-flash-device/8815

Click here to trigger a rebuild:
http://s-jenkins.ubuntu-ci:8080/job/mir-team-mir-development-branch-ci/1991/rebuild

review: Approve (continuous-integration)

=== modified file 'src/server/graphics/default_configuration.cpp'
--- src/server/graphics/default_configuration.cpp	2014-06-16 14:48:34 +0000
+++ src/server/graphics/default_configuration.cpp	2014-06-24 21:48:07 +0000
@@ -27,6 +27,7 @@
 
 #include "mir/graphics/buffer_initializer.h"
 #include "mir/graphics/gl_config.h"
+#include "mir/graphics/cursor.h"
 #include "program_factory.h"
 
 #include "mir/shared_library.h"
@@ -124,11 +125,23 @@
 std::shared_ptr<mg::Cursor>
 mir::DefaultServerConfiguration::the_cursor()
 {
+    struct NullCursor : public mg::Cursor
+    {
+        void show(mg::CursorImage const&) {}
+        void hide() {}
+        void move_to(geometry::Point) {}
+    };
     return cursor(
         [this]() -> std::shared_ptr<mg::Cursor>
         {
-            // For now we only support a hardware cursor.
-            return the_display()->create_hardware_cursor(the_default_cursor_image());
+            // We try to create a hardware cursor, as we have no software 
+            // cursor currently, if this fails we need to return
+            // a valid cursor object.
+            auto hardware_cursor = the_display()->create_hardware_cursor(the_default_cursor_image());
+            if (hardware_cursor)
+                return hardware_cursor;
+            else
+                return std::make_shared<NullCursor>();
         });
 }