Merge lp:~gcollura/ubuntu-calculator-app/reboot-delay-db-transactions into lp:ubuntu-calculator-app

[Giulio Collura]

Make use of Timer to delay db transactions.

I've inserted a QML Timer with a execute list property that enqueue all db transactions and execute them after a while (500 ms) to avoid to block the UI when inserting or deleting calculations.

[lp:~gcollura/ubuntu-calculator-app/reboot-delay-db-transactions]

64. By Giulio Collura on 2015-01-15

timer.start() is better than timer.restart() for various reasons

[Riccardo Padovani (rpadovani)]

After a talk with Giulio about timer.start() vs timer.restart() I approve this version.

Thanks!

review: Approve

[Ubuntu Phone Apps Jenkins Bot (ubuntu-phone-apps-jenkins-bot)]

PASSED: Continuous integration, rev:63
http://91.189.93.70:8080/job/ubuntu-calculator-app-reboot-ci/65/
Executed test runs:
    SUCCESS: http://91.189.93.70:8080/job/generic-mediumtests-vivid/681
        deb: http://91.189.93.70:8080/job/generic-mediumtests-vivid/681/artifact/work/output/*zip*/output.zip
    SUCCESS: http://91.189.93.70:8080/job/ubuntu-calculator-app-reboot-vivid-amd64-ci/65

Click here to trigger a rebuild:
http://91.189.93.70:8080/job/ubuntu-calculator-app-reboot-ci/65/rebuild

review: Approve (continuous-integration)

=== modified file 'app/engine/CalculationHistory.qml'
--- app/engine/CalculationHistory.qml	2015-01-08 18:21:28 +0000
+++ app/engine/CalculationHistory.qml	2015-01-15 13:45:32 +0000
@@ -39,6 +39,18 @@
         }
     }
 
+    Timer {
+        id: timer
+        interval: 500
+        property var execute: []
+        onTriggered: {
+            for (var i = 0; i < execute.length; i++) {
+                execute[i]();
+            }
+            execute = [];
+        }
+    }
+
     function openDatabase() {
         // Check if the database was already opened
         if (calculationHistoryDatabase !== null) return;
@@ -107,7 +119,10 @@
         var index = history.count - 1;
         // TODO: move this function to a plave that retards the execution to
         // improve performances
-        calculationHistory.addCalculationToDatabase(longFormula, result, date, index);
+        timer.execute.push(function() {
+            calculationHistory.addCalculationToDatabase(formula, result, date, index);
+        });
+        timer.start();
     }
 
     function addCalculationToDatabase(formula, result, date, index) {
@@ -136,10 +151,13 @@
 
         history.setProperty(id, "dbId", -1);
 
-        calculationHistoryDatabase.transaction(
-            function (tx) {
-                tx.executeSql('DELETE FROM Calculations WHERE dbId = ?', [dbId]);
-            }
-        );
+        timer.execute.push(function () {
+            calculationHistoryDatabase.transaction(
+                function (tx) {
+                    tx.executeSql('DELETE FROM Calculations WHERE dbId = ?', [dbId]);
+                }
+            )
+        });
+        timer.start();
     }
 }