refs #100 Swap backward a account in preferences

src/main/account.js

@@ -111,10 +111,27 @@ export default class Account {
       }
     )
     await this.updateAccount(backwarded._id, Object.assign(backwarded, { order: (backwarded.order + 1) }))
-    // Forward account order.
+    // Forward account order
     const updated = await this.updateAccount(ac._id, Object.assign(ac, { order: (ac.order - 1) }))
     return updated
   }
+
+  async backwardAccount (ac) {
+    const length = await this.countAuthorizedAccounts()
+    if (ac.order >= length) {
+      return ac.order
+    }
+    // Find account which is forwarded
+    const forwarded = await this.searchAccount(
+      {
+        order: ac.order + 1
+      }
+    )
+    await this.updateAccount(forwarded._id, Object.assign(forwarded, { order: (forwarded.order - 1) }))
+    // Backward account order
+    const updated = await this.updateAccount(ac._id, Object.assign(ac, { order: (ac.order + 1) }))
+    return updated
+  }
 }
 
 class EmptyRecordError {

src/main/index.js

@@ -320,6 +320,17 @@ ipcMain.on('forward-account', (event, acct) => {
     })
 })
 
+ipcMain.on('backward-account', (event, acct) => {
+  const account = new Account(db)
+  account.backwardAccount(acct)
+    .then(() => {
+      event.sender.send('response-backward-account')
+    })
+    .catch((err) => {
+      event.sender.send('error-backward-account', err)
+    })
+})
+
 // streaming
 let userStreaming = null
 

src/renderer/store/Preferences/Account.js

@@ -56,7 +56,17 @@ const Account = {
       })
     },
     backwardAccount ({ commit }, account) {
-
+      return new Promise((resolve, reject) => {
+        ipcRenderer.send('backward-account', account)
+        ipcRenderer.once('error-backward-account', (event, err) => {
+          ipcRenderer.removeAllListeners('response-forward-account')
+          reject(err)
+        })
+        ipcRenderer.once('response-backward-account', (event) => {
+          ipcRenderer.removeAllListeners('error-backward-account')
+          resolve()
+        })
+      })
     }
   }
 }