ui: Shorten references into InputEvent

An upcoming patch will alter how simple unions, like InputEvent, are
laid out, which will impact all lines of the form 'evt->u.XXX'
(expanding it to the longer 'evt->u.XXX.data').  For better
legibility in that patch, and less need for line wrapping, it's better
to use a temporary variable to reduce the effect of a layout change to
just the variable initializations, rather than every reference within
an InputEvent.

There was one instance in hid.c:hid_pointer_event() where the code
was referring to evt->u.rel inside the case label where evt->u.abs
is the correct name; thankfully, both members of the union have the
same type, so it happened to work, but it is now cleaner.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1457021813-10704-8-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

3 files changed, 57 insertions, 39 deletions

diff --git a/hw/input/hid.c b/hw/input/hid.c
index 81a85fb..41a9387 100644
--- a/hw/input/hid.c
+++ b/hw/input/hid.c
@@ -116,37 +116,42 @@ static void hid_pointer_event(DeviceState *dev, QemuConsole *src,
     };
     HIDState *hs = (HIDState *)dev;
     HIDPointerEvent *e;
+    InputMoveEvent *move;
+    InputBtnEvent *btn;
 
     assert(hs->n < QUEUE_LENGTH);
     e = &hs->ptr.queue[(hs->head + hs->n) & QUEUE_MASK];
 
     switch (evt->type) {
     case INPUT_EVENT_KIND_REL:
-        if (evt->u.rel->axis == INPUT_AXIS_X) {
-            e->xdx += evt->u.rel->value;
-        } else if (evt->u.rel->axis == INPUT_AXIS_Y) {
-            e->ydy += evt->u.rel->value;
+        move = evt->u.rel;
+        if (move->axis == INPUT_AXIS_X) {
+            e->xdx += move->value;
+        } else if (move->axis == INPUT_AXIS_Y) {
+            e->ydy += move->value;
         }
         break;
 
     case INPUT_EVENT_KIND_ABS:
-        if (evt->u.rel->axis == INPUT_AXIS_X) {
-            e->xdx = evt->u.rel->value;
-        } else if (evt->u.rel->axis == INPUT_AXIS_Y) {
-            e->ydy = evt->u.rel->value;
+        move = evt->u.abs;
+        if (move->axis == INPUT_AXIS_X) {
+            e->xdx = move->value;
+        } else if (move->axis == INPUT_AXIS_Y) {
+            e->ydy = move->value;
         }
         break;
 
     case INPUT_EVENT_KIND_BTN:
-        if (evt->u.btn->down) {
-            e->buttons_state |= bmap[evt->u.btn->button];
-            if (evt->u.btn->button == INPUT_BUTTON_WHEEL_UP) {
+        btn = evt->u.btn;
+        if (btn->down) {
+            e->buttons_state |= bmap[btn->button];
+            if (btn->button == INPUT_BUTTON_WHEEL_UP) {
                 e->dz--;
-            } else if (evt->u.btn->button == INPUT_BUTTON_WHEEL_DOWN) {
+            } else if (btn->button == INPUT_BUTTON_WHEEL_DOWN) {
                 e->dz++;
             }
         } else {
-            e->buttons_state &= ~bmap[evt->u.btn->button];
+            e->buttons_state &= ~bmap[btn->button];
         }
         break;
 
@@ -223,9 +228,10 @@ static void hid_keyboard_event(DeviceState *dev, QemuConsole *src,
     HIDState *hs = (HIDState *)dev;
     int scancodes[3], i, count;
     int slot;
+    InputKeyEvent *key = evt->u.key;
 
-    count = qemu_input_key_value_to_scancode(evt->u.key->key,
-                                             evt->u.key->down,
+    count = qemu_input_key_value_to_scancode(key->key,
+                                             key->down,
                                              scancodes);
     if (hs->n + count > QUEUE_LENGTH) {
         fprintf(stderr, "usb-kbd: warning: key event queue full\n");
diff --git a/hw/input/ps2.c b/hw/input/ps2.c
index 1bd0dde..86df1a0 100644
--- a/hw/input/ps2.c
+++ b/hw/input/ps2.c
@@ -182,10 +182,11 @@ static void ps2_keyboard_event(DeviceState *dev, QemuConsole *src,
 {
     PS2KbdState *s = (PS2KbdState *)dev;
     int scancodes[3], i, count;
+    InputKeyEvent *key = evt->u.key;
 
     qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
-    count = qemu_input_key_value_to_scancode(evt->u.key->key,
-                                             evt->u.key->down,
+    count = qemu_input_key_value_to_scancode(key->key,
+                                             key->down,
                                              scancodes);
     for (i = 0; i < count; i++) {
         ps2_put_keycode(s, scancodes[i]);
@@ -389,6 +390,8 @@ static void ps2_mouse_event(DeviceState *dev, QemuConsole *src,
         [INPUT_BUTTON_RIGHT]  = MOUSE_EVENT_RBUTTON,
     };
     PS2MouseState *s = (PS2MouseState *)dev;
+    InputMoveEvent *move;
+    InputBtnEvent *btn;
 
     /* check if deltas are recorded when disabled */
     if (!(s->mouse_status & MOUSE_STATUS_ENABLED))
@@ -396,23 +399,25 @@ static void ps2_mouse_event(DeviceState *dev, QemuConsole *src,
 
     switch (evt->type) {
     case INPUT_EVENT_KIND_REL:
-        if (evt->u.rel->axis == INPUT_AXIS_X) {
-            s->mouse_dx += evt->u.rel->value;
-        } else if (evt->u.rel->axis == INPUT_AXIS_Y) {
-            s->mouse_dy -= evt->u.rel->value;
+        move = evt->u.rel;
+        if (move->axis == INPUT_AXIS_X) {
+            s->mouse_dx += move->value;
+        } else if (move->axis == INPUT_AXIS_Y) {
+            s->mouse_dy -= move->value;
         }
         break;
 
     case INPUT_EVENT_KIND_BTN:
-        if (evt->u.btn->down) {
-            s->mouse_buttons |= bmap[evt->u.btn->button];
-            if (evt->u.btn->button == INPUT_BUTTON_WHEEL_UP) {
+        btn = evt->u.btn;
+        if (btn->down) {
+            s->mouse_buttons |= bmap[btn->button];
+            if (btn->button == INPUT_BUTTON_WHEEL_UP) {
                 s->mouse_dz--;
-            } else if (evt->u.btn->button == INPUT_BUTTON_WHEEL_DOWN) {
+            } else if (btn->button == INPUT_BUTTON_WHEEL_DOWN) {
                 s->mouse_dz++;
             }
         } else {
-            s->mouse_buttons &= ~bmap[evt->u.btn->button];
+            s->mouse_buttons &= ~bmap[btn->button];
         }
         break;
 
diff --git a/hw/input/virtio-input-hid.c b/hw/input/virtio-input-hid.c
index 9ca5395..e5480c3 100644
--- a/hw/input/virtio-input-hid.c
+++ b/hw/input/virtio-input-hid.c
@@ -191,46 +191,53 @@ static void virtio_input_handle_event(DeviceState *dev, QemuConsole *src,
     VirtIOInput *vinput = VIRTIO_INPUT(dev);
     virtio_input_event event;
     int qcode;
+    InputKeyEvent *key;
+    InputMoveEvent *move;
+    InputBtnEvent *btn;
 
     switch (evt->type) {
     case INPUT_EVENT_KIND_KEY:
-        qcode = qemu_input_key_value_to_qcode(evt->u.key->key);
+        key = evt->u.key;
+        qcode = qemu_input_key_value_to_qcode(key->key);
         if (qcode && keymap_qcode[qcode]) {
             event.type  = cpu_to_le16(EV_KEY);
             event.code  = cpu_to_le16(keymap_qcode[qcode]);
-            event.value = cpu_to_le32(evt->u.key->down ? 1 : 0);
+            event.value = cpu_to_le32(key->down ? 1 : 0);
             virtio_input_send(vinput, &event);
         } else {
-            if (evt->u.key->down) {
+            if (key->down) {
                 fprintf(stderr, "%s: unmapped key: %d [%s]\n", __func__,
                         qcode, QKeyCode_lookup[qcode]);
             }
         }
         break;
     case INPUT_EVENT_KIND_BTN:
-        if (keymap_button[evt->u.btn->button]) {
+        btn = evt->u.btn;
+        if (keymap_button[btn->button]) {
             event.type  = cpu_to_le16(EV_KEY);
-            event.code  = cpu_to_le16(keymap_button[evt->u.btn->button]);
-            event.value = cpu_to_le32(evt->u.btn->down ? 1 : 0);
+            event.code  = cpu_to_le16(keymap_button[btn->button]);
+            event.value = cpu_to_le32(btn->down ? 1 : 0);
             virtio_input_send(vinput, &event);
         } else {
-            if (evt->u.btn->down) {
+            if (btn->down) {
                 fprintf(stderr, "%s: unmapped button: %d [%s]\n", __func__,
-                        evt->u.btn->button,
-                        InputButton_lookup[evt->u.btn->button]);
+                        btn->button,
+                        InputButton_lookup[btn->button]);
             }
         }
         break;
     case INPUT_EVENT_KIND_REL:
+        move = evt->u.rel;
         event.type  = cpu_to_le16(EV_REL);
-        event.code  = cpu_to_le16(axismap_rel[evt->u.rel->axis]);
-        event.value = cpu_to_le32(evt->u.rel->value);
+        event.code  = cpu_to_le16(axismap_rel[move->axis]);
+        event.value = cpu_to_le32(move->value);
         virtio_input_send(vinput, &event);
         break;
     case INPUT_EVENT_KIND_ABS:
+        move = evt->u.abs;
         event.type  = cpu_to_le16(EV_ABS);
-        event.code  = cpu_to_le16(axismap_abs[evt->u.abs->axis]);
-        event.value = cpu_to_le32(evt->u.abs->value);
+        event.code  = cpu_to_le16(axismap_abs[move->axis]);
+        event.value = cpu_to_le32(move->value);
         virtio_input_send(vinput, &event);
         break;
     default: