frontend: policycheck: component to check the validity of a given policy code

* policycheck_view: user GUI to interact with (orbtk Widget)
* policycheck_state: rust code with helper methods

Signed-off-by: Ralf Zerres <ralf.zerres@networkx.de>

frontend/src/policycheck_state.rs

@@ -0,0 +1,136 @@
+use orbtk::prelude::*;
+
+use crate::{
+    base_state::BaseState,
+    //data::{PolicyData, PolicyList},
+    keys::*,
+};
+
+/// Actions that can execute on the task view.
+#[derive(Debug, Clone, Copy)]
+pub enum Action {
+    InputTextChanged(Entity),
+    ParseEntry(Entity),
+    RemoveFocus(Entity),
+    SetEntry(Entity),
+    TextChanged(Entity, usize),
+}
+
+/// Handles the requests of the `OverviewView`.
+#[derive(Default, AsAny)]
+pub struct PolicyCheckState {
+    action:Option<Action>,
+    last_focused: Option<Entity>,
+    pub text_box: Entity,
+    menu_button: Entity,
+    policy_code_valid: bool,
+}
+
+impl BaseState for PolicyCheckState {}
+
+impl PolicyCheckState {
+    /// Sets a new action.
+    pub fn action(&mut self, action: Action) {
+	self.action = action.into();
+    }
+
+
+    /// Parse and verify given policy code to match a valid policy data element.
+    fn parse_entry(&self, text_box: Entity, ctx: &mut Context) {
+	// Old style
+	//let length = ctx.get_widget(text_box).get::<String>("policy_code").len();
+	// New style
+	let  text_box = TextBox::get(ctx.widget());
+	println!("parsing policy code: {}", text_box.text());
+
+	// Parse policy code: "AS-123456789"
+	if let policy_code = text_box.text() {
+	    match policy_code {
+		_ => {
+		  println!("policycode: {} is valid!", policy_code);
+		}
+	    }
+	}
+    }
+
+    /// If TextBox 'policy_code' is empty, disable button "check"
+    /// otherwise enabled it.
+    fn set_check_button(&self, text_box: Entity, ctx: &mut Context) {
+	if ctx.get_widget(text_box).get::<String>("policy_code_check").is_empty() {
+	    ctx.get_widget(self.text_box).set("enabled", false);
+	} else {
+	    ctx.get_widget(self.text_box).set("enabled", true);
+	}
+
+	ctx.get_widget(self.text_box).update_theme_by_state(true);
+    }
+
+    /// Change status of given text box to edit mode.
+    fn set_entry(&self, text_box: Entity, ctx: &mut Context) {
+	if *ctx.get_widget(text_box).get::<bool>("focused") {
+	    ctx.get_widget(text_box).set("enabled", false);
+	    ctx.push_event_by_window(FocusEvent::RemoveFocus(text_box));
+	    return;
+	}
+
+	if let Some(old_focused_element) = ctx.window().get::<Global>("global").focused_widget {
+	    ctx.push_event_by_window(FocusEvent::RemoveFocus(old_focused_element));
+	}
+
+	ctx.get_widget(text_box).set("enabled", true);
+
+	// select all
+	ctx.get_widget(text_box)
+	    .get_mut::<TextSelection>("text_selection")
+	    .start_index = 0;
+	ctx.get_widget(text_box)
+	    .get_mut::<TextSelection>("text_selection")
+	    .length = ctx.get_widget(text_box).get::<String>("policy_code").len();
+	ctx.push_event_by_window(FocusEvent::RequestFocus(text_box));
+    }
+}
+
+impl State for PolicyCheckState {
+    fn init(&mut self, _: &mut Registry, ctx: &mut Context) {
+	self.menu_button = ctx
+	    .entity_of_child(ID_POLICY_CHECK_MENU_BUTTON)
+	    .expect("PolicyState.init: Can't find child 'Menu button'.");
+	self.text_box = ctx
+	    .entity_of_child(ID_POLICY_CHECK_TEXT_BOX)
+	    .expect("PolicyState.init: Can't find child 'Text Box'.");
+    }
+
+    fn update(&mut self, registry: &mut Registry, ctx: &mut Context) {
+	// clear focus on focus moved
+	if self.last_focused != ctx.window().get::<Global>("global").focused_widget {
+	    if let Some(last_focused) = self.last_focused {
+		ctx.get_widget(last_focused).set("focused", false);
+		ctx.get_widget(last_focused)
+		    .set("visibility", Visibility::Collapsed);
+	    }
+	}
+
+	if let Some(action) = self.action {
+	    match action {
+		Action::InputTextChanged(text_box) => {
+		    self.set_check_button(text_box, ctx);
+		}
+		Action::ParseEntry(text_box) => {
+		    self.parse_entry(text_box, ctx);
+		}
+		Action::RemoveFocus(text_box) => {
+		    ctx.get_widget(text_box).set("enabled", false);
+		    ctx.push_event_by_window(FocusEvent::RemoveFocus(text_box));
+		}
+		Action::SetEntry(text_box) => {
+		    self.last_focused = Some(text_box);
+		    self.set_entry(text_box, ctx);
+		}
+		Action::TextChanged(entity, index) => {
+		    self.set_entry(entity, ctx);
+		}
+	    }
+	}
+	self.action = None;
+    }
+}