Add a new 'ready' property to the PackageManager

If a project is using the new applications/installationDirMountPoint
config option which might delay loading the package database, it also
needs a signal to tell it when that database is in a consistent state.

Change-Id: I4b250f08c6dade2c675c3b742fe663afd992c1bd
Reviewed-by: Dominik Holland <dominik.holland@qt.io>
(cherry picked from commit d7a64b2163a00330ddb8d84eb0ab6c4c8261e0e9)
Reviewed-by: Robert Griebl <robert.griebl@qt.io>

3 files changed, 31 insertions, 0 deletions

diff --git a/qmltypes/QtApplicationManager/SystemUI/plugins.qmltypes b/qmltypes/QtApplicationManager/SystemUI/plugins.qmltypes
index b40c8b33..d9970045 100644
--- a/qmltypes/QtApplicationManager/SystemUI/plugins.qmltypes
+++ b/qmltypes/QtApplicationManager/SystemUI/plugins.qmltypes
@@ -665,11 +665,16 @@ Module {
         Property { name: "allowInstallationOfUnsignedPackages"; type: "bool"; isReadonly: true }
         Property { name: "developmentMode"; type: "bool"; isReadonly: true }
         Property { name: "hardwareId"; type: "string"; isReadonly: true }
+        Property { name: "ready"; type: "bool"; isReadonly: true }
         Property { name: "installationLocation"; type: "QVariantMap"; isReadonly: true }
         Property { name: "documentLocation"; type: "QVariantMap"; isReadonly: true }
         Property { name: "applicationUserIdSeparation"; type: "bool"; isReadonly: true }
         Property { name: "commonApplicationGroupId"; type: "uint"; isReadonly: true }
         Signal {
+            name: "readyChanged"
+            Parameter { name: "b"; type: "bool"; }
+        }
+        Signal {
             name: "countChanged"
         }
         Signal {
diff --git a/src/manager-lib/packagemanager.cpp b/src/manager-lib/packagemanager.cpp
index c174665f..7243a035 100644
--- a/src/manager-lib/packagemanager.cpp
+++ b/src/manager-lib/packagemanager.cpp
@@ -85,6 +85,10 @@
           application manager's \l{Configuration} will just lead to package (de-) installations
           failing instantly.
 
+    Please be aware that setting the \c{applications/installationDirMountPoint} configuration
+    option might delay the initialization of the package database. In this case, make sure to check
+    that the \l ready property is \c true before interacting with the PackageManager.
+
     The type is derived from \c QAbstractListModel, so it can be used directly as a model from QML.
 
     \target PackageManager Roles
@@ -379,6 +383,8 @@ void PackageManager::registerPackages()
     // now that we have a consistent pkg db, we can clean up the installed packages
     cleanupBrokenInstallations();
 
+    emit readyChanged(d->cleanupBrokenInstallationsDone);
+
 #if !defined(AM_DISABLE_INSTALLER)
     // something might have been queued already before the cleanup had finished
     triggerExecuteNextTask();
@@ -674,6 +680,22 @@ int PackageManager::indexOfPackage(const QString &id) const
     return -1;
 }
 
+/*!
+    \qmlproperty bool PackageManager::ready
+
+    Loading the package database might be delayed at startup if the
+    \c{applications/installationDirMountPoint} configuration option is set.
+
+    If your system is relying on this behavior, you should always check if the \l ready property is
+    \c true before accessing information about installed packages.
+    \note Calls to startPackageInstallation() and removePackage() while ready is still \c false
+          will be queued and executed once the package database is fully loaded.
+*/
+bool PackageManager::isReady() const
+{
+    return d->cleanupBrokenInstallationsDone;
+}
+
 bool PackageManager::developmentMode() const
 {
     return d->developmentMode;
diff --git a/src/manager-lib/packagemanager.h b/src/manager-lib/packagemanager.h
index 4be96f5d..befeefbd 100644
--- a/src/manager-lib/packagemanager.h
+++ b/src/manager-lib/packagemanager.h
@@ -90,6 +90,7 @@ class PackageManager : public QAbstractListModel
     Q_PROPERTY(bool developmentMode READ developmentMode CONSTANT)
     Q_PROPERTY(QString hardwareId READ hardwareId CONSTANT)
 
+    Q_PROPERTY(bool ready READ isReady NOTIFY readyChanged)
     Q_PROPERTY(QVariantMap installationLocation READ installationLocation CONSTANT)
     Q_PROPERTY(QVariantMap documentLocation READ documentLocation CONSTANT)
 
@@ -131,6 +132,8 @@ public:
     Q_INVOKABLE Package *package(const QString &id) const;
     Q_INVOKABLE int indexOfPackage(const QString &id) const;
 
+    bool isReady() const;
+
     bool developmentMode() const;
     void setDevelopmentMode(bool enable);
     bool allowInstallationOfUnsignedPackages() const;
@@ -180,6 +183,7 @@ public:
     PackageManagerInternalSignals internalSignals;
 
 signals:
+    Q_SCRIPTABLE void readyChanged(bool b);
     Q_SCRIPTABLE void countChanged();
 
     Q_SCRIPTABLE void packageAdded(const QString &id);