mirror of
https://github.com/Julow/Unexpected-Keyboard.git
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87 lines
2.9 KiB
Java
87 lines
2.9 KiB
Java
package juloo.keyboard2;
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import java.util.Arrays;
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public final class ComposeKey
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{
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/** Apply the pending compose sequence to [kv]. Returns [null] if no sequence
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matched. */
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public static KeyValue apply(int state, KeyValue kv)
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{
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switch (kv.getKind())
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{
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case Char:
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return apply(state, kv.getChar());
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case String:
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return apply(state, kv.getString());
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}
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return null;
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}
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/** Apply the pending compose sequence to char [c]. Returns [null] if no
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sequence matched. */
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public static KeyValue apply(int prev, char c)
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{
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char[] states = ComposeKeyData.states;
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char[] edges = ComposeKeyData.edges;
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int prev_length = edges[prev];
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int next = Arrays.binarySearch(states, prev + 1, prev + prev_length, c);
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if (next < 0)
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return null;
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next = edges[next];
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int next_header = states[next];
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if (next_header == 0) // Enter a new intermediate state.
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return KeyValue.makeComposePending(String.valueOf(c), next, 0);
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else if (next_header == 0xFFFF) // String final state
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{
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int next_length = edges[next];
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return KeyValue.getKeyByName(
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new String(states, next + 1, next_length - 1));
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}
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else // Character final state.
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return KeyValue.makeCharKey((char)next_header);
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}
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/** Apply each char of a string to a sequence. Returns [null] if no sequence
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matched. */
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public static KeyValue apply(int prev, String s)
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{
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final int len = s.length();
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int i = 0;
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if (len == 0) return null;
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while (true)
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{
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KeyValue k = apply(prev, s.charAt(i));
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i++;
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if (k == null) return null;
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if (i >= len) return k;
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if (k.getKind() != KeyValue.Kind.Compose_pending)
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return null; // Found a final state before the end of [s].
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prev = k.getPendingCompose();
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}
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}
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/** The state machine is comprised of two arrays.
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The [states] array represents the different states and the associated
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transitions:
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- The first cell is the header cell, [states[s]].
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- If the header is equal to [0],
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The remaining cells are the transitions characters, sorted
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alphabetically.
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- If the header is positive,
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This is a final state, [states[s]] is the result of the sequence.
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In this case, [edges[s]] must be equal to [1].
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- If the header is equal to [-1],
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This is a final state, the remaining cells represent the result string
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which starts at index [s + 1] and has a length of [edges[s] - 1].
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The [edges] array represents the transition state corresponding to each
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accepted inputs.
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- If [states[s]] is a header cell, [edges[s]] is the number of cells
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occupied by the state [s], including the header cell.
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- If [states[s]] is a transition, [edges[s]] is the index of the state to
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jump into.
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- If [states[s]] is a part of a final state, [edges[s]] is not used. */
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}
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