1 files changed, 169 insertions, 0 deletions
diff --git a/src/io/appium/droiddriver/Poller.java b/src/io/appium/droiddriver/Poller.java
new file mode 100644
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+++ b/src/io/appium/droiddriver/Poller.java
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+/*
+ * Copyright (C) 2013 DroidDriver committers
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.appium.droiddriver;
+
+import io.appium.droiddriver.exceptions.ElementNotFoundException;
+import io.appium.droiddriver.finders.Finder;
+
+/**
+ * Interface for polling mechanism.
+ */
+public interface Poller {
+  /**
+   * Interface for a callback to be invoked when {@link #pollFor} times out.
+   */
+  interface TimeoutListener {
+    /**
+     * Called when {@link #pollFor} times out. Should return quickly (no
+     * polling).
+     */
+    void onTimeout(DroidDriver driver, Finder finder);
+  }
+
+  /**
+   * Interface for a callback to be invoked when {@link #pollFor} polls.
+   */
+  interface PollingListener {
+    /**
+     * Called when {@link #pollFor} polls. Should return quickly (no polling).
+     */
+    void onPolling(DroidDriver driver, Finder finder);
+  }
+  /**
+   * Interface for removing a listener.
+   */
+  interface ListenerRemover {
+    /**
+     * A ListenerRemover that does nothing. Can be used as initial value for
+     * ListenerRemovers.
+     */
+    ListenerRemover NOP_LISTENER_REMOVER = new ListenerRemover() {
+      @Override
+      public void remove() {}
+    };
+
+    /**
+     * Removes the associated listener.
+     */
+    void remove();
+  }
+
+  /**
+   * Used by Poller to check conditions.
+   *
+   * @param <T> type of the value returned by {@link #check}
+   */
+  interface ConditionChecker<T> {
+    /**
+     * Checks condition that overriding methods provide.
+     *
+     * @throws UnsatisfiedConditionException If the condition is not met
+     */
+    T check(DroidDriver driver, Finder finder) throws UnsatisfiedConditionException;
+  }
+
+  /** Thrown to indicate condition not met. Used in {@link ConditionChecker}. */
+  @SuppressWarnings("serial")
+  class UnsatisfiedConditionException extends Exception {
+  }
+
+  /**
+   * A ConditionChecker that returns the matching {@link UiElement}.
+   */
+  ConditionChecker<UiElement> EXISTS = new ConditionChecker<UiElement>() {
+    @Override
+    public UiElement check(DroidDriver driver, Finder finder) throws UnsatisfiedConditionException {
+      try {
+        return driver.find(finder);
+      } catch (ElementNotFoundException e) {
+        throw new UnsatisfiedConditionException();
+      }
+    }
+
+    @Override
+    public String toString() {
+      return "to appear";
+    }
+  };
+  /**
+   * A ConditionChecker that does not throw only if the matching
+   * {@link UiElement} is gone.
+   */
+  ConditionChecker<Void> GONE = new ConditionChecker<Void>() {
+    @Override
+    public Void check(DroidDriver driver, Finder finder) throws UnsatisfiedConditionException {
+      try {
+        // "find" does not call refreshUiElementTree, while "has" calls
+        driver.find(finder);
+        throw new UnsatisfiedConditionException();
+      } catch (ElementNotFoundException enfe) {
+        return null;
+      }
+    }
+
+    @Override
+    public String toString() {
+      return "to disappear";
+    }
+  };
+
+  /**
+   * Polls until {@code checker} does not throw
+   * {@link UnsatisfiedConditionException}, up to the default timeout.
+   *
+   * @return An object of type T returned by {@code checker}
+   */
+  <T> T pollFor(DroidDriver driver, Finder finder, ConditionChecker<T> checker);
+
+  /**
+   * Polls until {@code checker} does not throw
+   * {@link UnsatisfiedConditionException}, up to {@code timeoutMillis}.
+   *
+   * @return An object of type T returned by {@code checker}
+   */
+  <T> T pollFor(DroidDriver driver, Finder finder, ConditionChecker<T> checker, long timeoutMillis);
+
+  /**
+   * Adds a {@link TimeoutListener}.
+   */
+  ListenerRemover addListener(TimeoutListener timeoutListener);
+
+  /**
+   * Adds a {@link PollingListener}.
+   */
+  ListenerRemover addListener(PollingListener pollingListener);
+
+  /**
+   * Sets default timeoutMillis.
+   */
+  void setTimeoutMillis(long timeoutMillis);
+
+  /**
+   * @return default timeoutMillis
+   */
+  long getTimeoutMillis();
+
+  /**
+   * Sets intervalMillis.
+   */
+  void setIntervalMillis(long intervalMillis);
+
+  /**
+   * @return intervalMillis
+   */
+  long getIntervalMillis();
+}