create wallet in android, enhance password dialogs

client/electrum4a.py

@@ -351,7 +351,9 @@ settings_layout = make_layout("""
 def get_history_values(n):
     values = []
     h = wallet.get_tx_history()
-    for i in range(n):
+
+    length = min(n, len(h))
+    for i in range(length):
         line = h[-i-1]
         v = line['value']
         try:
@@ -500,9 +502,22 @@ def pay_to(recipient, amount, fee, label):
 
 
 def recover():
-    if not modal_question("Wallet not found","restore from seed?"):
+
+    droid.dialogCreateAlert("Wallet not found","Do you want to create a new wallet, or restore an existing one?")
+    droid.dialogSetPositiveButtonText('Create')
+    droid.dialogSetNeutralButtonText('Restore')
+    droid.dialogSetNegativeButtonText('Cancel')
+    droid.dialogShow()
+    response = droid.dialogGetResponse().result
+    droid.dialogDismiss()
+    if response.get('which') == 'negative':
         exit(1)
 
+    is_recovery = response.get('which') == 'neutral'
+
+    if not is_recovery:
+        wallet.new_seed(None)
+    else:
         if modal_question("Input method",None,'QR Code', 'mnemonic'):
             code = droid.scanBarcode()
             r = code.result
@@ -518,30 +533,32 @@ def recover():
                 modal_dialog('error: could not decode this seed')
                 exit(1)
 
-    if not modal_question('Seed', seed ):
-        exit(1)
-
         wallet.seed = str(seed)
-    wallet.init_mpk( wallet.seed )
 
-    change_password_dialog()
+    modal_dialog('Your seed is:', wallet.seed)
+    modal_dialog('Mnemonic code:', ' '.join(mnemonic.mn_encode(wallet.seed)) )
 
-    droid.dialogCreateSpinnerProgress("Electrum", "recovering wallet...")
+    msg = "recovering wallet..." if is_recovery else "creating wallet..."
+    droid.dialogCreateSpinnerProgress("Electrum", msg)
     droid.dialogShow()
+
+    wallet.init_mpk( wallet.seed )
     WalletSynchronizer(wallet,True).start()
     wallet.update()
-    wallet.save()
+
     droid.dialogDismiss()
     droid.vibrate()
 
+    if is_recovery:
         if wallet.is_found():
-        # history and addressbook
             wallet.update_tx_history()
             wallet.fill_addressbook()
             modal_dialog("recovery successful")
         else:
             if not modal_question("no transactions found for this seed","do you want to keep this wallet?"):
                 exit(1)
+
+    change_password_dialog()
     wallet.save()
 
 
@@ -761,8 +778,8 @@ def seed_dialog():
 
 def change_password_dialog():
     if wallet.use_encryption:
-        password  = droid.dialogGetPassword('Current password').result
+        password  = droid.dialogGetPassword('Your wallet is encrypted').result
-        if not password: return
+        if password is None: return
     else:
         password = None
 
@@ -773,6 +790,10 @@ def change_password_dialog():
         return
 
     new_password  = droid.dialogGetPassword('Choose a password').result
+    if new_password == None:
+        return
+
+    if new_password != '':
         password2  = droid.dialogGetPassword('Confirm new password').result
         if new_password != password2:
             modal_dialog('error','passwords do not match')
@@ -782,7 +803,7 @@ def change_password_dialog():
     if new_password:
         modal_dialog('Password updated','your wallet is encrypted')
     else:
-        modal_dialog('Password removed','your wallet is not encrypted')
+        modal_dialog('No password','your wallet is not encrypted')
         
 
 def settings_loop():

client/wallet.py

@@ -340,7 +340,7 @@ class Wallet:
 
     def new_seed(self, password):
         seed = "%032x"%ecdsa.util.randrange( pow(2,128) )
-        self.init_mpk(seed)
+        #self.init_mpk(seed)
         # encrypt
         self.seed = self.pw_encode( seed, password )
 
@@ -850,7 +850,8 @@ class Wallet:
         return target, signing_addr, auth_name
 
     def update_password(self, seed, new_password):
-        self.use_encryption = (new_password != '')
+        if new_password == '': new_password = None
+        self.use_encryption = (new_password != None)
         self.seed = self.pw_encode( seed, new_password)
         for k in self.imported_keys.keys():
             a = self.imported_keys[k]