[geary/mjog/folder-actions: 3/7] Plugins.FolderContext: Add support for showing folder info bars

[Michael Gratton <mjog src gnome org>]

commit 0e7d30f8cbd767b67315525fe1d4032fd0df5909
Author: Michael Gratton <mike vee net>
Date:   Wed Mar 18 18:57:14 2020 +1100

    Plugins.FolderContext: Add support for showing folder info bars
    
    Add Plugin.InfoBar to allow plugins to describe an info bar, add
    methods to FolderContext to allow adding and removing them when
    folders are displayed and implement them. Add a InfoBarStack to the
    MainWindow for displaying folder info bars.

 po/POTFILES.in                                     |  1 +
 .../application/application-folder-context.vala    | 44 ++++++++++++++++++++++
 .../application/application-main-window.vala       | 10 +++++
 src/client/meson.build                             |  1 +
 src/client/plugin/plugin-folder-extension.vala     | 25 ++++++++++++
 src/client/plugin/plugin-info-bar.vala             | 44 ++++++++++++++++++++++
 ui/application-main-window.ui                      |  1 +
 7 files changed, 126 insertions(+)
---
diff --git a/po/POTFILES.in b/po/POTFILES.in
index 9b29d4d7..066079ae 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -96,6 +96,7 @@ src/client/plugin/plugin-error.vala
 src/client/plugin/plugin-folder-extension.vala
 src/client/plugin/plugin-folder-store.vala
 src/client/plugin/plugin-folder.vala
+src/client/plugin/plugin-info-bar.vala
 src/client/plugin/plugin-notification-extension.vala
 src/client/plugin/plugin-plugin-base.vala
 src/client/plugin/plugin-trusted-extension.vala
diff --git a/src/client/application/application-folder-context.vala 
b/src/client/application/application-folder-context.vala
index 28209afa..6686e052 100644
--- a/src/client/application/application-folder-context.vala
+++ b/src/client/application/application-folder-context.vala
@@ -12,6 +12,21 @@ internal class Application.FolderContext :
     Geary.BaseObject, Plugin.FolderContext {
 
 
+    private class PluginInfoBar : Components.InfoBar {
+
+
+        private Plugin.InfoBar plugin;
+
+
+        public PluginInfoBar(Plugin.InfoBar plugin) {
+            base(plugin.status, plugin.description);
+            this.show_close_button = plugin.show_close_button;
+            this.plugin = plugin;
+        }
+
+    }
+
+
     private unowned Client application;
     private FolderStoreFactory folders_factory;
     private Plugin.FolderStore folders;
@@ -29,6 +44,35 @@ internal class Application.FolderContext :
         return this.folders;
     }
 
+    public void add_folder_info_bar(Plugin.Folder selected,
+                                    Plugin.InfoBar infobar,
+                                    uint priority) {
+        Geary.Folder? folder = this.folders_factory.get_engine_folder(selected);
+        if (folder != null) {
+            foreach (MainWindow main in this.application.get_main_windows()) {
+                if (main.selected_folder == folder) {
+                    main.conversation_list_info_bars.add(
+                        new PluginInfoBar(infobar)
+                    );
+                }
+            }
+        }
+    }
+
+    public void remove_folder_info_bar(Plugin.Folder selected,
+                                       Plugin.InfoBar infobar) {
+        Geary.Folder? folder = this.folders_factory.get_engine_folder(selected);
+        if (folder != null) {
+            foreach (MainWindow main in this.application.get_main_windows()) {
+                if (main.selected_folder == folder) {
+                    main.conversation_list_info_bars.remove(
+                        new PluginInfoBar(infobar)
+                    );
+                }
+            }
+        }
+    }
+
     internal void destroy() {
         this.folders_factory.destroy_folder_store(this.folders);
     }
diff --git a/src/client/application/application-main-window.vala 
b/src/client/application/application-main-window.vala
index 160d5103..2b97de96 100644
--- a/src/client/application/application-main-window.vala
+++ b/src/client/application/application-main-window.vala
@@ -285,6 +285,11 @@ public class Application.MainWindow :
     public SearchBar search_bar { get; private set; }
     public ConversationListView conversation_list_view  { get; private set; }
     public ConversationViewer conversation_viewer { get; private set; }
+
+    public Components.InfoBarStack conversation_list_info_bars {
+        get; private set; default = new Components.InfoBarStack.exclusive();
+    }
+
     public StatusBar status_bar { get; private set; default = new StatusBar(); }
 
     private Controller controller;
@@ -686,6 +691,8 @@ public class Application.MainWindow :
                 this.conversation_list_view.set_model(null);
             }
 
+            this.conversation_list_info_bars.remove_all();
+
             // With everything disposed of, update existing window
             // state
 
@@ -1214,6 +1221,9 @@ public class Application.MainWindow :
         this.folder_list_scrolled.add(this.folder_list);
 
         // Conversation list
+        this.conversation_box.pack_start(
+            this.conversation_list_info_bars, false, false, 0
+        );
         this.conversation_list_view = new ConversationListView(
             this.application.config
         );
diff --git a/src/client/meson.build b/src/client/meson.build
index 02a7eb9b..c1140f18 100644
--- a/src/client/meson.build
+++ b/src/client/meson.build
@@ -105,6 +105,7 @@ geary_client_vala_sources = files(
   'plugin/plugin-folder-extension.vala',
   'plugin/plugin-folder-store.vala',
   'plugin/plugin-folder.vala',
+  'plugin/plugin-info-bar.vala',
   'plugin/plugin-notification-extension.vala',
   'plugin/plugin-plugin-base.vala',
   'plugin/plugin-trusted-extension.vala',
diff --git a/src/client/plugin/plugin-folder-extension.vala b/src/client/plugin/plugin-folder-extension.vala
index fc5ac372..11722cae 100644
--- a/src/client/plugin/plugin-folder-extension.vala
+++ b/src/client/plugin/plugin-folder-extension.vala
@@ -50,4 +50,29 @@ public interface Plugin.FolderContext : Geary.BaseObject {
     public abstract async FolderStore get_folders()
         throws Error.PERMISSION_DENIED;
 
+    /**
+     * Adds an info bar to a folder, if selected.
+     *
+     * The info bar will be shown for the given folder if it is
+     * currently selected in any main window, which can be determined
+     * by connecting to the {@link folder_selected} signal. Further,
+     * if multiple info bars are added for the same folder, only the
+     * one with a higher priority will be shown. If that is closed or
+     * removed, the second highest will be shown, and so on. Once the
+     * selected folder changes, the info bars will be automatically
+     * removed.
+     */
+    public abstract void add_folder_info_bar(Folder selected,
+                                             InfoBar infobar,
+                                             uint priority);
+
+    /**
+     * Removes an info bar from a folder, if selected.
+     *
+     * Removes the info bar from the given folder if it is currently
+     * selected in any main window.
+     */
+    public abstract void remove_folder_info_bar(Folder selected,
+                                                InfoBar infobar);
+
 }
diff --git a/src/client/plugin/plugin-info-bar.vala b/src/client/plugin/plugin-info-bar.vala
new file mode 100644
index 00000000..9e4e3937
--- /dev/null
+++ b/src/client/plugin/plugin-info-bar.vala
@@ -0,0 +1,44 @@
+/*
+ * Copyright © 2020 Michael Gratton <mike vee net>
+ *
+ * This software is licensed under the GNU Lesser General Public License
+ * (version 2.1 or later). See the COPYING file in this distribution.
+ */
+
+/**
+ * Enables plugins to report ongoing status messages.
+ *
+ * The info bar supports two text descriptions, a short (approximately
+ * 20 charters at most) status message, and a possibly longer
+ * explanation of what is happening.
+ */
+public class Plugin.InfoBar : Geary.BaseObject {
+
+
+    /**
+     * A short, human-readable status message.
+     *
+     * This should ideally be less than 20 characters long.
+     */
+    public string status { get; private set; }
+
+    /**
+     * An optional, longer human-readable explanation of the status.
+     *
+     * This provides additional information and context for {@link
+     * status}.
+     */
+    public string? description { get; private set; }
+
+    /** Determines if a close button is displayed by the info bar. */
+    public bool show_close_button { get; set; default = false; }
+
+
+    /** Constructs a new info bar with the given status. */
+    public InfoBar(string status,
+                   string? description = null) {
+        this.status = status;
+        this.description = description;
+    }
+
+}
diff --git a/ui/application-main-window.ui b/ui/application-main-window.ui
index 981da65f..ab362ae2 100644
--- a/ui/application-main-window.ui
+++ b/ui/application-main-window.ui
@@ -96,6 +96,7 @@
                               <packing>
                                 <property name="expand">True</property>
                                 <property name="fill">True</property>
+                                <property name="pack_type">end</property>
                                 <property name="position">0</property>
                               </packing>
                             </child>