fix: allow auto-collapse of header when viewing trainwreck txn

tailbone/templates/form.mako

@@ -16,10 +16,53 @@
 </%def>
 
 <%def name="page_content()">
+  % if main_form_collapsible:
+      <${b}-collapse class="panel"
+                     % if request.use_oruga:
+                         v-model:open="mainFormPanelOpen"
+                     % else:
+                         :open.sync="mainFormPanelOpen"
+                     % endif
+                     >
+        <template #trigger="props">
+          <div class="panel-heading"
+               role="button"
+               style="cursor: pointer;">
+
+            ## TODO: for some reason buefy will "reuse" the icon
+            ## element in such a way that its display does not
+            ## refresh.  so to work around that, we use different
+            ## structure for the two icons, so buefy is forced to
+            ## re-draw
+
+            <b-icon v-if="props.open"
+                    pack="fas"
+                    icon="caret-down">
+            </b-icon>
+
+            <span v-if="!props.open">
+              <b-icon pack="fas"
+                      icon="caret-right">
+              </b-icon>
+            </span>
+
+            &nbsp;
+            <strong>Transaction Header</strong>
+          </div>
+        </template>
+        <div class="panel-block">
           <div class="form-wrapper">
             <br />
             ${self.render_form()}
           </div>
+        </div>
+      </${b}-collapse>
+  % else:
+      <div class="form-wrapper">
+        <br />
+        ${self.render_form()}
+      </div>
+  % endif
 </%def>
 
 <%def name="render_this_page()">
@@ -54,6 +97,15 @@
   ${parent.render_this_page_template()}
 </%def>
 
+<%def name="modify_this_page_vars()">
+  ${parent.modify_this_page_vars()}
+  % if main_form_collapsible:
+      <script>
+        ThisPageData.mainFormPanelOpen = ${'false' if main_form_autocollapse else 'true'}
+      </script>
+  % endif
+</%def>
+
 <%def name="finalize_this_page_vars()">
   ${parent.finalize_this_page_vars()}
   % if form is not Undefined:

tailbone/templates/trainwreck/transactions/configure.mako

@@ -3,6 +3,19 @@
 
 <%def name="form_content()">
 
+  <h3 class="block is-size-3">Display</h3>
+  <div class="block" style="padding-left: 2rem;">
+
+    <b-field>
+      <b-checkbox name="tailbone.trainwreck.view_txn.autocollapse_header"
+                  v-model="simpleSettings['tailbone.trainwreck.view_txn.autocollapse_header']"
+                  native-value="true"
+                  @input="settingsNeedSaved = true">
+        Auto-collapse header when viewing transaction
+      </b-checkbox>
+    </b-field>
+  </div>
+
   <h3 class="block is-size-3">Rotation</h3>
   <div class="block" style="padding-left: 2rem;">
 

tailbone/views/trainwreck/base.py

@@ -256,6 +256,7 @@ class TransactionView(MasterView):
 
     def template_kwargs_view(self, **kwargs):
         kwargs = super().template_kwargs_view(**kwargs)
+        config = self.rattail_config
 
         form = kwargs['form']
         if 'custorder_xref_markers' in form:
@@ -268,6 +269,12 @@ class TransactionView(MasterView):
                 })
             kwargs['custorder_xref_markers_data'] = markers
 
+        # collapse header
+        kwargs['main_form_collapsible'] = True
+        kwargs['main_form_autocollapse'] = config.get_bool(
+            'tailbone.trainwreck.view_txn.autocollapse_header',
+            default=False)
+
         return kwargs
 
     def get_xref_buttons(self, txn):
@@ -419,6 +426,11 @@ class TransactionView(MasterView):
     def configure_get_simple_settings(self):
         return [
 
+            # display
+            {'section': 'tailbone',
+             'option': 'trainwreck.view_txn.autocollapse_header',
+             'type': bool},
+
             # rotation
             {'section': 'trainwreck',
              'option': 'use_rotation',